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proceedings of the

WesternLarge Herd

Dairy ManagementConference

2nd

Las Vegas, NevadaApril 5-8, 1995

Section Chairman: Ruth Blauwiekel, Washington State University

9:15 a.m. Welcome — John Smith, New Mexico State University

9:25 “Optimizing BST Response Through NutritionAnd Feeding Management”Carl Coppock, Coppock Nutritional Services, Laredo, TX

10:05 “Reproduction And Health Management In BST Herds”James Ferguson, University of Pennsylvania

10:45 “Economics Of Using BST”John Smith, New Mexico State UniversityKen Bailey and David Hardin, University of Missouri

11:25 “Making BST Work: The Producer Experience”Romulo Escobar Valdez, Escobar Dairy, Juarez, MexicoRon St. John, Alliance Dairies, Trenton, FLTom Thompson, Stotz Dairy, Buckeye, AZ

12:25 p.m. LUNCH

Section Chairman: Don Klingborg, University of California-Davis

1:45 “Footwarts In Dairy Cattle: Current UnderstandingOf A Complex Disease”Richard Walker, University of California-Davis

2:25 “Colostral Management: How Good Is Your Program?”Frank Garry, Colorado State UniversityScott Wells, USDA/APHIS Veterinary Services

3:05 BREAK

Section Chairman: Bill Wailes, Colorado State University

3:20 “Rational Treatment Of Clinical Mastitis”Walt Guterbock, U.C. Davis

4:00 “Neosporosis: A Newly Recognized CauseOf Abortion In Dairy Cattle”Pat Conrad, U.C. Davis

Section Chairman: Dennis Armstrong, University of Arizona

8:30 a.m. “Design And Performance Of Milking Systems”Graeme Mein, University of Wisconsin

9:10 “Making Manure Nutrient Management Work For You”Deanne Morse and Larry Schwankl, U.C. Davis

9:50 “Freestall Housing Design For Comfort & Convenience”Dan McFarland, Penn State University

10:30 BREAK

Section Chairman: Richard Norell, University of Idaho

10:45 “Dairying In The Future:Some Questions You May Want To Ask”Rich Cotta, San Joaquin Valley Dairymen, Los Banos, CA

11:25 “Economic Decision Support Systems For Dairies”Mike Delorenzo, University of Florida

12:05 p.m. LUNCH

Section Chairman: Chris Woelfel, Texas A&M University

1:25 “Resolving Conflict In Family-OwnedAgricultural Businesses”Guy & Michelle Hutt, University of Southern Maine

2:25 “Economic Impact Of Bull Choices, A.I. Or Otherwise”Ben McDaniel, North Carolina State University

3:05 BREAK

Section Chairman: Don Bath, University of California-Davis

3:20 “Managing The Milking Parlor For Profitability”Dennis Armstrong, Univ. of Arizona; John Smith, NewMexico State Univ.; Craig Thomas and Dave Bray, Univ.of Florida; Mike Gamroth, Oregon State University

4:00 “Economical Feeding And Management Practices ForHerds Approaching 30,000-lb. Rolling Herd Averages”Brad Houston, Price’s Roswell Dairy, Roswell, NMDennis Lagler, Lagler’s Dairy, Vancouver, WA

Section Chairman: Ron Bowman Utah State University

8:30 a.m. “ Feeding To Make Money: Managing NutrientsIn The Total Herd”Charles Sniffen, Miner Research Institute, Chazy, NY

9:10 “Management Strategies For TMR Feeding Systems”Jim Spain, University of Missouri

9:50 “Minimizing Transitional Stress For Close-Up Dry Cows:Field Experiences And Applications”Jimmy Horner, Horner Nutrition Service, Decatur, TX

10:30 BREAK

Section Chairman: Mike Gamroth, Oregon State University

10:45 “Facts And Fallacies About The Uterus After Calving”Donald Klingborg, U.C. Davis

11:25 “Dairying And The New Social Ethic For Animals”Bernie Rollin, Colorado State University

12:05 CONFERENCE ADJOURN

2 2ND WESTERN LARGE HERD DAIRY MANAGEMENT CONFERENCE • LAS VEGAS, NV • APRIL 6-8, 1995

Program:Thursday April 6

Friday April 7

Saturday April 8

Welcome!to the 2nd Western Large Herd Dairy Management Confer-ence, presented by the Cooperative Extension Services fromthe Western United States. We have prepared a program thatwe believe will assist you in continuing to be the leaders inthe world’s most efficient milk production industry, andthereby in maintaining a healthy industry.

Dennis Armstrong, University of Arizona – Co-chairmanMike Gamroth, Oregon State University – Co-chairmanJohn Smith, New Mexico State University – Co-chairmanDonald Bath, University of California-DavisRuth Blauwiekel, Washington State UniversityRon Bowman, Utah State UniversityDennis Halladay, The Western Dairyman MagazineDonald Klingborg, University of California-DavisRichard Norell, University of IdahoWilliam Wailes, Colorado State UniversityChris Woelfel, Texas A&M University

2ND WESTERN LARGE HERD DAIRY MANAGEMENT CONFERENCE • LAS VEGAS, NV • APRIL 6-8, 1995 3

Conference Organizing Committee members (kneeling and seated l-r ):Chris Woelfel, Mike Gamroth, John Smith, DonBath, Ruth Blauwiekel, Dennis Armstrong, and Richard Norell. (Standing, l-r): Donald Klingborg, Ron Bowman, and BillWailes.

page

“Optimizing BST Response Through Nutrition And Feeding Management” by Carl Coppock 5

“Bovine Somatotropine: Effects On Reproduction” by James Ferguson 11

“Financial Implications Of BST” by John Smith, Ken Bailey and David Hardin 19

“Making BST Work: The Producer Experience”with dairy producers Ron St. John, Tom Thompson and Romulo Escobar Valdez 27

“Footwarts In Dairy Cattle: Current Understanding Of A Complex Disease” by Richard Walker 33

“Colostral Management: How Good Is Your Program?” by Franklyn Garry and Scott Wells 41

“Rational Treatment Of Clinical Mastitis” by Walter Guterbock 49

“Neosporosis: A Newly Recognized Cause Of Abortion In Dairy Cattle”by Patricia Conrad, Mark Anderson, and Bradd Barr 61

“Design And Performance Of Milking Systems” by Graeme Mein 69

“Making Manure Nutrient Management Work For You” by Deanne Morse and Larry Schwankl 79

“Freestall Housing Guidelines: Details To Enhance Management” by Dan McFarland 89

“Dairying In The Future: Some Questions You May Want To Ask” by Richard Cotta 103

“Economic Decision Support Systems For Dairies” by Mike DeLorenzo and Craig Thomas 113

“Managing Conflict In Agricultural Businesses” by Guy Hutt 125

“Economic Impact Of Bull Choices, A.I. Or Otherwise” by Ben McDaniel 133

“Managing The Milking Parlor For Profitability”by Dennis Armstrong, Craig Thomas, John Smith, Mike Gamroth, and David Bray 139

“Economical Feeding And Management Practices For HerdsApproaching 30,000-lb. Rolling Herd Averages” 147with dairy producers Bradley Houston and Dennis Lagler

“ Feeding To Make Money: Managing Nutrients In The Total Herd” by Charles Sniffen 153

“Management Strategies For TMR Feeding Systems” by Jim Spain 161

“Minimizing Transitional Stress For Close-Up Dry Cows:Field Experiences And Applications” by Jimmy Horner 169

“Facts And Fallacies About The Uterus After Calving” by Donald Klingborg 173

“Dairying And The New Social Ethic For Animals” by Bernard Rollin 179


Index Of Presentations:

Proceedings of the 2nd W estern Large Herd Dairy Management ConferenceEditor – Mike Gamroth, Oregon State University

Layout & Production – Dennis Halladay, The Western Dairyman Magazine

Optimizing BSTResponse Through

Nutrition AndFeeding Management

By Carl E. CoppockCoppock Nutritional Services

902 Dellwood Dr.Laredo, TX 78041-2119

210-791-2238fax 210-791-2238


BB ST is here. Now the challenge is to maximizeprofit through its use. Someone said, “BST isa shortcut to genetic progress.” Genetic

progress for milk in Holsteins has been about 260lbs per year. In 10 years this is 2,600 lbs. If BST isused beginning at 63 days postpartum and it is con-tinued for 242 days and an average response of 10lbs/day is obtained, then 2,420 lbs more milk willbe obained in one lactation. This is equivalent toover 9 years of genetic progress in one lactation.Adopting BST is like a very sudden shift to a highergear in a machine with an engine capable of deliv-ering the torque to move at the higher speed.

Studies with the respiration chambers at USDA-Beltsville, MD, showed that neither digestive normetabolic efficiency was changed when BST wasused. Therefore, the increased milk which occurswith BST use must be paid for with increased feed.There is no free lunch with the increased milk fromuse of BST. Cows respond to BST in 3 ways:

a). They produce more milk.b). After a lag they eat more feed.c). They produce more heat.Therefore, use of BST affects two primary man-

agement systems: nutritional management and envi-ronmental management.

Nutritional Management – Dry PeriodThe dry period presents a window of opportunity

to:a). Replenish nutrient reserves if needed.b). To prepare tissues of the cow for the stresses

of parturition and lactation which follow.c). To eliminate mammary gland infections if they

are present.Stopping the use of BST should be part of the dry-

ing off procedure because production will declinefollowing its removal. Body condition score shouldbe about 3.5 at the end of the dry period. This sim-ple, though subjective, method of evaluating bodyenergy reserves is one of the most useful and criti-cally needed tools to make the results of BST a con-tinuing success. For whatever reason(s), a numberof cows are finishing lactation without the nutrientreserves needed to begin a new lactation with the

production which they are capable of achieving.Therefore, the dry period provides the time to restorethese reserves and body condition score is the toolto show how much replenishment is needed.

The NRC (1989) gives a pregnancy allowance forenergy of about 30% of maintenance. Both can bemet by 25 lbs. of an excellent grass hay. With regardto lead feeding, I recommend 4-6 lbs./cow/day dur-ing the three weeks prepartum, of the concentratefed to the lactating cows. Oetzel et al. (1988),showed that even with prepartum diets high in cal-cium, 100g/d each of ammonium chloride andammonium sulfate for 21 days prepartum reducedthe incidence of milk fever from 17% to 4% in 48Holstein cows. I suggest to use these anionic saltswith great caution.

Nutritional Management – Postpartum CowUnder drylot housing, the totally mixed ration

(TMR) system in which cows are fed for ad libitumconsumption is a superb way to feed cows. Defin-ition: A TMR is a quantitative mixture of all dietaryingredients, blended thoroughly enough to preventsepara-tion and sorting, formulated to specific nutri-ent levels and offered free choice. When cows aregiven a choice of feeds, a significant minority ofcows will “unbalance” their rations. Examples ofchoices include:

a). alfalfa hay vs. corn silageb). mineral supplementsc). whole cottonseed vs. other feeds. Diet formulation should begin with comprehen-

sive water, forage and feed testing. Drinking watermay carry from 50% to 100% or more of the require-ments for sodium, sulfur, chloride, and other min-eral elements. The reason book values cannot beused for precise formulation is that there is great vari-ation in economically important nutrients. Andprobably greater variation occurs in most of thebyproducts than occurs in conventional feed grains.

In formulation, one should consider:a). costb). palatabilityc). predicted dry matter (DM) intake (optimal

water)


Optimizing BST Response Through Nutrition And Feeding Management

d). energy (NEl), fats, nonstructural carbohydratese). fibers, ADFand NDFf). protein, with a range in degradable/undegrad-

able proteinf). 7 macro and 7 micro mineral elements, includ-

ing buffering capabilityh). water consumption and compositioni). excesses as well as deficiencies.The intended nutrient profile in the final mixture

should be confirmed. Strive for maximal energy inearly lactation. We won’t be able to close the gapbetween feed energy eaten and energy required, butwith good nutritional management, it is possible toelevate both curves. However, if there is a weaknessor deficiency in the formulation, it will likely mani-fest itself more severely with use of BST.

An advantage for feeding supplemental fats (SF) isthe increased energy density and the lower starchwhich results if the SF is substituted for cereal grains.This suggests that by increasing energy density, anincrease in energy consumption will result. This is trueif dry matter intake is maintained or nearly so. Nega-tive effects sometimes occur with SFs; these includelower fiber digestibility, reduced feed intake, and usu-ally reduced milk casein synthesis. But both forms ofSF are needed: oilseeds and ruminally inert fats.

Use of BST will cause an increase in milk yieldwithin 2-4 days of first use, although maximalresponse requires 4 to 6 weeks of continuous use.A recent survey showed that dairymen were gettingan average of 10.7 lbs of milk per cow per day fromBST use. Ten pounds of additional milk will requireabout 4 lbs more of feed dry matter of a well bal-anced TMR. But there is a lag of 4-6 weeks beforethe appetite increases for the additional feed. Dur-ing this lag period, the nutrients to pay for the addi-tional milk must come from body stores, feed, or acombination of the two.

There is no free lunch here; the increase in milkyield must be paid for with feed nutrients at somepoint. Feed nutrients must be available when theappetite increases so that cows have the chance toreplenish nutrient reserves as lactation advances. Arecent study from Michigan (Speicher et al., 1994)shows that the effects of BST and 3X milking are addi-tive, but not completely so. The primiparous cowsresponded more to the combination of 3X and BSTthan did the multiparous cows (see Table 1 below).

Heat Stress ManagementRemember, as Dennis Armstrong says: “a cow is

a little furnace!” The greater the feed intake, the hot-ter the furnace. As body temperature increases, the

cow responds by reducing herfeed intake, probably as a pro-tective mechanism, and milkproduction soon drops. Duringheat stress, a behavioralresponse of cows fed feeds sep-arately is to reduce hay intakemore than or before concen-trate. Therefore, fiber intake isreduced with possible prob-lems under this feeding system.

Some nutrient requirementsare increased by heat stress:

a). Largely as a result ofpanting, a heat-stressed cowwill have an energy require-ment for maintenance of 120-130% of normal.


Table 1: Effect Of BST And Milking Frequency (2X vs. 3X) on Daily FCMProduction By Multiparous And Primiparous Holstein Cows*

–––– Control –––– –––– BST ––––No. FCM No. FCM Diff. due

Cows lbs/day Cows lbs/day to BSTMultiparous

3X 16 75.4 16 80.9 5.52X 17 65.0 14 78.7 3.7

Difference 10.4 2.2

Primiparous3X 14 65.7 14 75.8 10.12X 13 58.6 14 70.8 12.2

Difference 7.1 5.0

*Speicher et al., J. Dairy Sci. 77: 2509. 1994.

panting, a heat-stressed cow will have an energy requirement for maintenance of 120-1 30% of normal.

b). Up to 50% more water will be drunk. As long as the drinking water is cooler than the body temperature of the cow, the consumed water adsorbs some of the cow's body heat. So if one is fortunate to have cold well water, do not bring that cold water up to an open trough where it will warm up, but keep it shaded or use one of the insulated tanks to keep it cold until the cows drink it.

c). Potassium: increase to 1 .3-1.5% (West, 1994). d). Sodium: increase to .35% e). Magnesium35: .35% (West, (1 994) f). Chlorine: .35%? Are there dietary adjustments that will maintain

net energy intake and simultaneously reduce metabolic heat production?

Chandler (1 994) noted that some feed ingredients have lower heat increments than others, and that these should be emphasized in hot weather. Heat increment is defined as the increase in heat production which occurs when animals eat feed. For example, feeds with low heat increment include whole cottonseed, roasted soybeans, tallow and the ruminally escape fats. Low fiber ingredients usually result in less HI than high fiber feeds - corn silage less thanmost hays.

Both dietary deficiencies and excesses cause extra heat production.

Degradable protein and undegradable protein in the appropriate relationship has

reduced heat stress in some trials. High yielding cows produce more heat than low

yielding cows. Technologies not economic at low production may become so at yields achieveable with BST. In otherwords, use of BST will help to pay for the heat stress technology which allows it to work in hot weather.

Shades. The black and white cow does not belong in the sun in the Southern U.S. during summer.

a). In a Georgia summer study (West et al., 1990), cows with shade as the only heat stress alleviation and given BST produced more milk, ate equal dry matter (DM), had higher body temperatures, but lost body weight and condition.

b). In an Arizona study (Huber, 1994) from March through August, cows given BST maintained a 10 Ibs. advantage over controls, even though both groups dropped more that 20 Ibs. per day during this interval. But the cows in this study were cooled with high technology evaporative coolers.

c). Relevant to more humid areas, Florida work-

these two devices – 1.5 minutes sprinkling and 14minutes of fan. These are especially valuable in theholding areas as well as in freestall barns and overcows at the feed manger.

Armstrong (1994) has an excellent summary oncooling options with the following priorities:

a). Solid shade for all milking and dry cows.b). Holding pen cooling.c). Exit lane cooling.d). Corral shade cooling.e). Feed manger cooling. f). Covered feed manger.

Other Management FeaturesUse of BST will make longer calving intervals

(C.I.) more profitable. Over 10 years ago, Holmannet al. (1994) showed that in contrast to the usual rec-ommendation of a 12-mos. C.I. as being ideal, 13months actually produced slightly more incomeover feed cost per cow per day of C.I. ($4.11 vs.$4.08), and a 15-mos. C.I. showed no substantialloss ($4.08) compared to 13-mos. This was a bud-geting simulation study which assumed that TMRincome maximizing rations were fed, 65 days drywere provided, and 30% of the cows were <36 mos.of age and 70% were older than 36 mos.

As Ferry (1994) recently noted, “Regardless ofbreeding strategy, BST supplementation prolongs theperiod of profitable production, widening the win-dow of opportunity to achieve conception, andincreasing average herd life”. In turn, cows that failto rebreed or are deliberately marked to not rebreedwill have longer and more profitable herd livesthrough the use of supplemental BST.

Summary:1. Use of BST makes cows of all genetic abilities

better cows that produce more milk. When they eatmore feed, they produce more heat.

2. Greater milk yields mean correspondinglygreater nutrient requirements; fortunately, increasedappetite occurs in BST treated cows some 4-5 weeksafter treatment begins, which allows restoration ofbody reserves in later lactation if feed nutrients areavailable.

3. Diet formulation should be comprehensiveand based on detailed feed and water testing.

4. Some nutrient requirements are increased byheat stress, but careful diet formulation can resolvemost of these.

5. A cow is a little furnace — she has much heatto get rid of. Some reduction in heat production bythe cow can be achieved by selection of feedstuffswhich have lower heat increments.

6. An array of technologies is now available to helpthe cow dissipate the large amount of heat she pro-duces, plus the heat she receives from her environ-ment. Use of BST will help to pay for the heat stresstechnology which allows it to work in hot weather.

7. In summer, cows will produce as much milkas the heat stress management allows them to pro-duce. We have bred dairy cows to be heat-generat-ing animals, metabolic thoroughbreds that will pun-ish themselves with elevated body temperatures andsharply increased respiration rates in order to sus-tain the high yields they were bred to produce. Ifcontinuing increases in yields are to be sustained,cows must have protection from the high radiantheat of summer, have help in dissipating the largeamounts of heat they produce, and receive dietswhich minimize the heat associated with the diges-tion and metabolism of feed.

Selected References:1. Armstrong, D. V. 1994. Environmental modi-

fications to reduce heat stress. The Dairyman, 75:No. 4, p. 24.

2. Bray, D. R., D. K. Beede and R. A. Bucklin.1990. Recommendations for a sprinkler and fanevaporative cooling system for dairy cattle. IFASPubl., U. Florida, DS-29.

3. Chandler, Paul. 1994. Is heat increment offeeds an asset or liability to milk production? Feed-stuffs, 66: No. 15, p. 12 (April 11).

4. Ferry, J. 1994. Effect of management and herdlife, in Management strategies for dairy cattle: a newparadigm. Proc. Monsanto Tech. Symp. p. 25.

5. Hartnell, G. F. 1994. Bovine somatotropin inthe dairy industry. Prof. Anim. Sci., 10:85-101.

6. Holmann, F. J., C. R. Shumway, R. W. Blake,R. B. Schwart, and E. M. Sudweeks. 1984. Economicvalue of days open for Holstein cows of alternative


milk yields with varying calving intervals. J. DairySci. 67: 636.

7. Huber, J. T. 1994. Feeding strategies during hotweather. p. 35 in Proc. 5th Florida Ruminant Nutr.Symp., Gainesville. National Research Council.1989. Nutrient requirements of dairy cattle. 6th Rev.ed., Nat’l. Acad. Sci., Washington, DC.

8. Oetzel, G. R., J. D. Olson, C. R. Curtis, and M.J. Fettman. 1988. Ammonium chloride and ammo-nium sulfate for prevention of parturient paresis indairy cows. J. Dairy Sci. 71:3302.

9. Speicher, J. A., H. A. Tucker, R. W. Ashley, E.P. Stanisiewski, J. F. Boucher, and C. J. Sniffen. 1994.

Production responses of cows to recombinantlyderived bovine somatotrophin and to frequency ofmilking. J. Dairy Sci., 77:2509.

10. West, J. W., B. G. Mullinix, J. C. Johnson, Jr.,K. A. Ash and V. N. Taylor. 1990. Effects of bovinesomatotropin on dry matter intake, milk yield, andbody temperature in Holstein and Jersey cows dur-ing heat stress. J. Dairy Sci., 73: 2896.

11. West, J. W. 1994. Improving intake and per-formance of dairy cows during heat stress condi-tions. p. 14 in Proc. Mid-South Rum. Nutr. Conf.,April 21-22. TX Nutr. Council.

notes

Optimizing BST Response Through Nutrition And Feeding Management


Bovine Somatotropin:

Effects On Reproduction

By James D. Ferguson VMD, MS, University of Pennsylvania

Center of Animal Health and Productivity School of Veterinary Medicine

New Bolton Center 382 W. Street Road

Kennett Square, PA 19348

fax 21 544-4724 21 5-444-5800

eproductive efficiency effects profit in dairy ter that determines CI and calves born per year. herds by influencing milk produced per day, Combined with the PR, the breeding period will R calves born per year, and replacement losses determine the total pregnant animals. Decreasing

from forced culling 4 7,9, 13. Since rates of return are 3/1 CR and/or HDR and extending the V W P increase in early lactation compared to 1/1 in late lactation, the CI. This reduces milk/day and calves born/year, and 50% of profit from milk production is realized thereby reducing herd profit. Pregnancy rate (PR) in the first 100 days of lactation, profit and cash flow captures the effects of HDR and CR in one variable- are potentially maximized when COWS calve every In dairy herds it is profitable to achieve 85% preg- 12 months, given typical lactation profiles. The opti- nancy Or higher in COWS which are in the breeding mal time period between successive calvings (calv- pool, and profit is maximized when 80% of cows ing interval (CI)) is a function of the shape of the lac- become pregnant prior to 120 days postcalving at tation curve, replacement calf value and future a PR of 35%. potential survival in the herd Altering the lactation Using lactation data from a 400-COW dairy We function by using bovine somatotropin may alter the examined production responses through two lacta- optimal CI. tions for cows with VWP of 50, 80, 11 0, 140 days

Bovine somatotropin (BST) increases milk pro- and 100% PR. We modeled production for 50 cows, duction post peak lactation and has a slightly neg- 35% first lactation, 20% second lactation, and 45% ative effect on conception rate (CR) 1,5,6,17,18 19. Due to third and greater lactation, through two sequential the lower CR, CI has been longer and fewer COWS lactations. Initially, we did not consider replace- have become pregnant when given BST and vol- ment, but were interested reproductive factors untary waiting period has not been altered (Table which resulted in maximum production in this 1). Since BST increases milk production post lacta- cohortofcowsoverthistime period. Voluntary wait- tion peak, it has been speculated that it may be more ing period could be varied, as could PR and breed- profitable to have a longer CI in cows receiving BST. ing period. Initial breeding period was set to 270 In addition, although fewer cows may become preg- days from the WVp and could be exknded to 420 nant, BST may be used to extend lactation in open days from the VWp- cows, thus reducing the negative effects of fewer As days open increase from 50 through 140 days, pregnant cows on milk produced per day. However, milk declines by .06 Ibs/day (Figure 1). Thus, it is extended CI and fewer pregnant cows may decrease most profitable to get COWS Pregnant early- TO inves- returns if these are bad decisions economically. tigate theeffects of BST on this relationship we then Many studies have examined the economic aspects examined injections from the ninth week Of lacta- of using BST based on milk yield response and cost tion- of BST but few studies have examined the inter- Posilac® (Monsanto) is approved for use in lac- action of BST use with reproductive management tating dairy COWS from the ninth week of lactation5. on farm profit. This paper will explorer those issues. Typical production responses have been 8-1 5 Ibs.

Calving Interval And BST of milk. Injections must be given every 14 days to Calving interval is a function of conception rate maintain the production response. Production re-

(CR), heat detection rate (HDR), voluntary waiting sponse declines slightly in COWS over 200 days in period (VWP) and breeding period (days following milk5. Production oscillates with the 14day injec- the VWP which cows will still be inseminated). Con- tion schedule, peaking 7-1 0 days post injection. w e ception rate influences semen usage. Heat detec- examined production responses of 5,10, and 15 Ibs. tion and conception rate determine pregnancy rate with varying VWp and PR to examine the effect Of

(PR, the proportion of cows which become preg- BST on milk/day over two sequential lactations. nant every 21 days). Pregnancy rate is the parame- Injection was given beginning the 9th week of lac-

tation and response could be varied to exam the interaction of BST with days open.

Again, PR was set to 1 00% V W P was varied from 50 to 1 40 days and BST response was 0,5, 10 or 1 5 Ib. (Figure 1). In this case the WVP would represent days open. Milk produced per day decreased .060 Ibs/day from 58.82 Ibs/day as days open increased from 50 to 140 days. If BST caused a 5 Ib. increase in milk, baseline milk increased to 61.99 Ibs/day but increasing days open was still associated with a .055 Ib/day decline in milk produced per day. If BST increased milk 10 Ib., then baseline production was 65.22 Ibs/day and the decline in production per day was .051 Ibs/day With a fifteen pound increase in milk from BST injections, baseline milk was 68.47 Ibs/day but still declined at .046 Ibs/day with increasing days open (Figure 1). The decline in milk with extended days open was reduced with increasing BST response but not abolished. Using BST rnin- imized losses in milk/day with extended days open,

but highest production was associated with 50 days open.

However, dairy herds do not have PR of 100%. The average herd has a PR of 25%, and most herds range from a low of 15 to a high of 35%. Therefore herds have cows with varying distributions of days open as a function of PR. At very low PR (<=30%) milk/day, declines steeply (Figure 2). Extending the V W P to 80 days across all PR reduces milk/day, but the decrease is not as great at PR below 35% (Fig- ure 2). Injections of BST, resulting in 5,10, or 15 Ib. of milk response, increase milk/day above baseline rates across all PR, but production is maximal when PR is above 35% (Figure 3). L o w PR extend CI, lower milk produced per day and calves born per year. Injections of BST increase milk/day, at any given level of PR. However, milk/day is maximized with VWP of SO days and PR equal to and above 35%. Thus, it does not appear that extending CI is the best decision to maximize milk production with BST. It

would appear to be optimal to maintain short CI with BST.

the minimum and maximum milk/day if the incidence of periparturient problems is 0% at PR is

Interactions with Periparturient Problems <20% (minimum) and PR>70% (maximum). Increasing PR above 40% increases milk/day within ranges observed with no periparturient problems, but not to levels of 0% disorders. Extending VWP at typical PR of .25 in herds would be a costly decision. To delay breeding 30 days because of periparturient problems would reduce milk 2.1 lbs/day, at a PR of .25. It would only be profitable to make this decision if the cost of health interventions was more than the milk loss. However, to delay because of problems also reduces production/day in normal cows. Thus, this appears to be a bad decisions.

If BST increases milk 5,1 0, or 15 pounds, then it can mitigate the production losses with periparturient problems (Figure 4). However, only BST in combination with short VWP and high PR can restore

Cows with periparturierit problems may have reduced fertility and reduced production. It has been suggested that extending CI would decrease the yearly costs associated with periparturient problems, and by using BST, lactations could be profitably extended to offset the losses associated with extended CI. To investigate these interactions, incidence of periparturient problems was varied from 10 to 50% with reduction in fertility of from 25 to 90% and production declines of 10 to 30% in cows with problems.

If the incidence of periparturient problems ranges from 10 to 30% and milk production declines by 10% in these cows, milk/day is reduced at all PR (Figure 4). The horizontal lines in figure 4 represent

milk/day to levels achievable with no periparturient problems and high reproductive efficiency. If BST response were 10 Ib. or more and milk losses with periparturient problems were 10%, then milk pro duced/day would approach baseline values if PR were 30% or higher. However, it should be noted that these levels don’t approach maximum yields if periparturient problems were 0%

Management Conclusions Thus it appears reproductiveefficiency and strate-

gies should not be altered with BST. BST may offset some of the negative effects of low PR (<35%) common in most herds by increasing milk/day.

Reproductive Effects - Overview Pregnancy Prevalence. Presented in Table 1 is PP

for control and BST treated cows summarized from literature reports (3,5,10,17,18). PP was significantly reduced in BST treated cows. Pregnancy was most effected in primiparous cows in data summarized by Cole et al. (3). Older cows, the effects of BST on pregnancy seemed to be largely a function of milk yield (3). If milk yield increased in a predictable fash-

ion to BST injection, then PP was slightly reduced, and the reduction was consistent with increased milk yield (3).

Conception Rate a . Overall, cows receiving BST had slightly lower CR (5) to no significant reduction in CR (3,5 and Table 1). Days open increased (Table 1). Under current management schemes, with voluntary wait periods of 50- 60 days, BST use will lower PP, but in a manner consistent with increased milk yield. CR in the fertile population will be similar to current CR, but total semen use may increase due to an increase in cows failing to become pregnant earlier. This early depres- sion in CR may be related to energy balance and initial losses in body condition just after initiation of BST (14-16,19). Feeding management will interact with reproductive management and influence the CR response seen in individual herds. Cows failing to become pregnant may actually

stay in the herd longer, due to BST injection pro- longing lactation yields. Thus although increasing forced replacement, herd turnover per year may

decrease, as cull cows may be milked longer due to BST injection.

Physiologic Effects On Reproduction Changes in endocrine pattern in BST treated cows

have been slight. Several studies have shown BST treatment is associated with increased plasma progesterone" 12. GnRH induced luteinizing hormone (LH) output from the pituitary was higher in BST treated cows, and LH pulse frequency increased in BST treated cows12. These slight changes in progesterone and LH are difficult to interpret relative to their potential impact on reproductive function.

Most studies have reported no effect of low to average doses of BST on expression of estrous or estrous cycling. High doses of BST have been reported to increase estrous cycle length and decrease estrous expression. Most studies suggest

little effect on first ovulation, estrous cycle length and estrus expression.

High doses of BST (>= 50 mg/d) have been reported to increase early embryonic death. Initia- tion of BST in cows during early pregnancy (25 to 40 d postbreeding) should probably be avoided. This may explain why PP decreases with no change in CR in the cows which become pregnant. Cows which fail to maintain pregnancy may fail to become pregnant, whereas cows which maintain pregnancy due so in a fashion consistent with herd performance.

Extrapolating from field studies and based on the time postpartum of initiation of BST injection, the effects of BST on the physiology of reproduction appear to be minor and will not present major problems to dairy producers.

Weight Change And Body Condition Most studies have reported less weight and body

condition gain in BST-treated cows 1,2,5,15,16,18,19. Initia- tion of BST treatment decreases energy balance. Dry matter intake increases, usually 4 to 8 weeks after BST initiation (5). A decrease in energy balance does not mean cows are returning to negative energy balance. They may only be less positive, particularly with BST initiation at 60 days postpartum. BST partitions nutrients from body tissue to milk, so it is not surprising that BSTcows gain body weight and body condition slower than nontreated cows. In most studies, condition by next calving was not different in the BST cows. Thus body repletion occurs, but producers will have to monitor condition change in late lactation to ensure adequate body reserves for next lactation. This does not appear to be different than current practices used to manage body reserves in high producing herds.

Managing rations to minimize change in body condition with initiation of BST should aid in preventing reduction in CR in the first month after BST treatment.

Milk yield responses to BST injection in cows

treated for two and three successive lactations have shown responses equal to the first year response (26,28,46). With proper management of body reserves, cows will respond equally well to BST in subsequent lactations.

Conclusion Bovine somatotropin is a management tool which

can be used to alter production within a herd of cows. Maintaining reproductive efficiency with BST is important to optimizing herd production, just as it is without BST use.

Financial Implications

Of rBST

ecombinant bovine somatotropin (rBST) first became available to U.S. dairy producers in February, 1994 after Food and Drug Admin-

istration approval. The product approved, called Posilac, is manufactured and marketed by Monsanto Company. As new technologies such as Posilac become available, it is essential that dairy producers understand how to use them profitably.

A number of factors effect the profitability of cows supplemented with rBST. Some of these include: feed and labor cost, price of the product, milk price, and achieved milk production response. Other factors that affect the profitable use of rBST are number of cows milked, times per day milking, and percent of the herd receiving rBST treatment.

The objective of this paper is to evaluate the economics of rBST in a commercial setting for large dairy herds. We will consider the financial implica-

tions Of rBST in terms of the whole herd, and on a per COW and per hundredweight (cwt.) basis. We will also consider rBST use under 2 times and 3 times a day milking. Information presented in this paper will help dairy producer develop a profitable program to effectively use rBST.

Feed Cost The dry matter intake of the dairy cows supple-

mented with rBST will increase 2-7 weeks after the initiation of treatment. Rations should be balanced to meet the requirements for body condition and milk production.

The amount of energy required to produce an additional pound of milk is .31 Mcal(4). This assumes that the maintenance requirements of the COW have been satisfied. If a ration contains .78 Mcals per pound of dry matter a dairy cow will have to consume an additional .397 pounds of dry mat-

ter per pound of milk response, or 3.97 pounds of Labor Dairy producers will need to reallocate existing

labor and/or hire more labor in order to effectively implement an rBST program. Additional labor will be used to keep injection records, inject cows, and body condition score cows. The rBST program can be as simple or complex as desired. The labor cost of an rBST program will likely vary significantly from farm to farm. For example, some dairy producers will keep injection records and body condition score individual cows. Other producers will assign cows to pens which the entire pen will be supplemented with rBST every 14 days.

In this paper, we injected all eligible cows every 14 days starting at 67 days post-partum. We also

dry matter per 10 pounds of milk. Table 1 on the opposite page lists the feed costs

required to produce an additional pound of milk at different costs per pound of dry matter (5¢-1 2¢). Feed costs in Table 1 are based on .31 Mcals per pound of milk above maintenance and a ration containing .78 Mcals per pound of dry matter. In Table 2 we have calculated the daily feed cost associated with supplementing cows with rBST at different response levels (4-1 5 Ibs). Using a combination of the information on Table 1 and 2 a producer can determine the additional feed cost associated with supplementing cows with rBST at different levels of production.

assumed an additional labor cost of 2¢ per treated cow per day.

Price Of rBST The price of Posilac is currently $5.80 per dose.

The actual cost of using Posilac, however, will vary by state due to differences in sales taxes. In this paper we assumed a sales tax of 7.25%. That would raise the cost of Posilac to $6.22 per dose, or 44¢ per day of treatment.

Profitability On A Per Cow Basis Milk response to rBST and the market price of

milk will have dramatic effects on the profitability of using rBST. The profitability of using supplemental rBST on a per cow basis is evaluated in Table 3. We used 12 milk response levels (4-1 5 pounds) and six mailbox milk price levels ($9-$1 4)'. The costs of Posilac and labor remained constant in the analysis. Feed cost, however, increased with the level of milk response.

The mailbox milk price will have a significant effect on profitability at a given level of milk response to rBST use. For example, a $9 milk price

at a 10 Ibs. milk response generates a profit of 12¢e per treated cow. That compares to a 42¢ profit per treated cow at a $12 milk priceatthesamemilkre sponse level.

On the other hand, the level of milk response to rBST use is also extremely important in effectively using this new technology. If we assume a constant milk price of $1 0 per cwt, an 8 Ibs. response to rBST will generate a 1 5¢ per treated cow profit compared to a 35¢ per treated cow profit from a 12 Ibs. re sponse.

Financial Implications Of Using rBST In Dairy Herds Milking 2 Times And 3 Times Per Day In this section we will analyze the profitability of

rBST in a representative Western dairy herd. One issue that will be explored is whether it is more profitable to use rBST with twice a day (2x) milking and three times per day (3x) milking. While 3X milking results in a production increase, 2X milking allows

more total cows to be milked through the parlor. This analysis will take place using a dairy financial simulation model called Commercial Agriculture Dairy Simulation Model (CADSIM).

The Model (CADSIM) The CADSIM model was developed by the Uni-

versity of Missouri Extension to help dairy producers evaluatethe financial implications of expansion or management changes. The model is a whole-farm financial planning tool that incorporates a detailed dairy enterprise with an ability to project financial statements over a 5-year planning horizon. The model consists of five interactive modules: Produc- tion, Feed, Labor, Loan, and Expense. These modules are then used to calculate financial statements and measures that lenders and/or investors will need to evaluate a loan or investment package.

The model simulates production and financial information over a 5-year period. A dairy enterprise budget is then estimated from a simple average of the financial information in the profit/loss statement over the 5-year period.

Assumptions Used In The Model The profitability of rBST use was evaluated by

simulating the profitability of a representative West- ern dairy operation. This was accomplished by entering production, expense, and financial data into the CADSIM model in order to develop a baseline. The data used for this exercise was provided by the accounting firm of Genske, Mulder & Com- pany.'

We assumed a herd size of 1,I70 cows (milking and dry) that would milk 3X with daily average production of 66.1 Ibs. per cow with no BST. That would translate into a 365-day rolling herd average of 20,470 Ibs. The following were also assumed:

$12.50 gross milk price 13-month calving interval 60-day dry period 29% cull rate 2% death rate 3% of milk not shipped

Two rations were fed for milking cows: a 2 week start-up ration (cost of $3.24 per day) and a high production ration ($3.73 per day) for the balance of the days in milk.

Labor was calculated based on time spent milking, feeding, and other chores. Annual milking labor was calculated based on 3X milking, 1 hour per shift cleanup and setup, and throughput of 160 cows per hour (assumes a double-20 parallel parlor). Total annual labor was calculated as follows:

23,662 hours for milking 5,265 hours for feeding and other chores $202,486 hired labor bill $40,000 for salaried herdsman $1 4,549 total company benefits

The baseline is presented in the first three columns of table 4. Notice that the baseline indicates a total herd profit of $1 30,895, which is $11 2 per cow and 55¢ per hundredweight of milk sold. This scenario is called the baseline and all other scenarios discussed below are compared to it.

Using rBST 7.25% sales tax. Use of supplemental rBST is considered in order

to improve overall farm profits. The following assumptions are made regarding use of rBST

1 . All eligible cows receive rBST supplementation according to label.

2. Supplementation begins at day 67, with a 10 Ibs. per day response.

3. rBST costs of $5.80 per 14-day dose, with a

4. Cows supplemented with rBST for 268 days. 5. Annual feed cost per cow increased by $74

6. Labor hours per cow increased by 0.71. The financial implications of rBST use on the rep-

resentative farm is presented in columns 4-6 in table 4. Use of rBST improves total milk production and production per cow. Feed costs for the herd and per

per cow.

cow increase due to greater feed intake. Labor costs for the herd increased $6,504 over the baseline when rBST was used. An additional .71 hours of

program. Labor costs on a per cwt. basis, however, decline due to greater milk production levels. Mar-

capital retains) increases for the herd and per cow due to greater milk production levels. The cost of

keting costs (for hauling, federal assessments, and

the rBST is estima d at $1 08 per cow per year, or 47¢/cwt. Most of r costs remain the same on a per herd and per cow asis, but fall on a per cwt. basis

profits increased b $66,781 from rBST use, or by $57 per cow and 1 ¢/cwt. of milk sold.

Switchin Back To 2X Milking Use of rBST has allowed many producers to retain

cows in the milk s ring that would otherwise have

labor was used per cow per year to manage the rBST due to greater mil production. Overall net farm

been culled for low milk production without rBST use. This change has resulted in lower cull rates and an increase in herd sizes. In order to milk more cows in a 24-hour period without expanding the parlor, thedecision could be made to switch from 3X milking back to 2X milking. But is this move profitable?

To evaluate this, one must first consider what happens to profitability when switching from 3X without rBST use to 2X without rBST. The following assumptions are made:

Switch from 3X to 2X milking. . Lower cow throughput from 160 to 150 cows

Lower the herd lactation curve by 10%. Lower the cull rate to 19% in year 1 and 25%

Purchase 976 cows in year 1 to increase herd

Reduce ration costs by 5% per day. The herd size was increased in order to keep the

parlor milking 22 hours per day. Daily milk production was reduced in order to reflect the switch from 3X to 2X milking. The financial results are presented in columns 1-3 in table 5. They indicate that switching from 3X milking without rBST use to 2X milking without rBST use will lower annual profits by $102,651 or by $96 per cow. While gross income for the herd increases under 2X milking, per cow income declines due to lower milk production per cow. Total feed costs increase due to more cows, but declines on a per cow basis due to lower nutritional demands. Total interests costs increasedue to debt on purchased cows. Likewise, all other costs increase on a herd basis, but decrease slightly on a per cow basis due to more cows to spread these cost

per hour (due to more milk per milking).

in year 2.

size to 1,773 cows.

Ranking The Results: 1. The most profitable scenario Is rBST

use with 3X milking. 2. The least profitable scenario Is 2X

milking without rBST use. 3. The difference in total profits between

these two extremes is $1 69,432. 4. Total profit for the 2X scenario with

rBST use is comparable to herd profits for the 3X scenario without rBST use.

5. There is no gain in profits from switching from 3X without rBST to 2X with rBST. 6. Milking 2X is less profitable than

milking 3X with or without rBST.

over. What happens if rBST is used with 2X milking?

To determine the effect, assumptions were used in the 3X scenario with rBST use. The financial implications of rBST use with 2X milking are presented in columns 4-6 in Table 5. This scenario indicates a $57 per cow improvement in profits relative to the 2X scenario without rBST.

Making BSTWork: TheProducer

ExperiencePanelists:

Ron St. John, Alliance Dairies, Trenton, FLTom Thompson, Stotz Dairy, Buckeye, AZ

Romulo Escobar Valdez, Escobar Dairy, Juarez, Mexico

Moderator:Ruth Blauwiekel, Extension Dairy Specialist

Washington State University

2ND WESTERN LARGE HERD DAIRY MANAGEMENT CONFERENCE • LAS VEGAS, NV • APRIL 6-8, 1995 2 7

BB ovine somatotropin (BST) was approved foruse in the United States in November of 1993,although a Congressional moratorium de-

layed its release onto the market until February of1994. In spite of the initial controversy surroundingits use, BST has made significant inroads amongdairy producers, particularly in larger herds in theWestern states. At the end of 1994, Monsanto esti-mated that 10-11% of dairy herds in the U.S. wereutilizing BST. USDA estimated that as many as 25%of dairy managers would be using BST in their herdsby the end of 1995.

Other countries in the western hemisphere thathave approved the use of BST in dairy cows includeBrazil, Costa Rica, and Mexico. Mexican dairy pro-ducers have had access to BST since October of1990. This panel discussion brings together the man-agers of three large dairy herds from the U.S. andMexico to describe their experiences with this newmanagement technology.

Could you briefly describe your herd?

Romulo Escobar Valdez: “In 1983, the EscobarDairy began an expansion program with new facil-ities and 2,000 cows. There are now 4,150 cows ona drylot dairy, with 3,680 milking. On the dairy arealso about 300 close-up heifers. About 2,500 re-placements are on a separate farm, along with 500bulls being raised for beef. The cows are managedin four separate units, each with its own 24-cowBou-Matic polygon. Alfalfa, and sorghum and rye-grass for silage are grown under irrigation on 1,750acres. Between 130 and 140 workers are employedat the farm.”

(Note: The dairy uses a consulting nutritionist, aveterinarian, and an equipment specialist. Currentherd average is 24,240 lbs. of milk on 3X milking,the highest producing herd in Mexico. Romulo isowner and manager of the dairy.)

Ron St. John: Ron is managing partner of AllianceDairies, a 2,800-cow Florida dairy located 60 milessouth of the Georgia state line. The dairy also raises2,000 head of young stock and about half of its own

forages in order to utilize manure generated by thefarm, growing corn, millet and rye for silage. Thereare 44 employees. The dairy employs a consultingnutritionist and also a veterinarian who is both a con-sultant and a ‘hands-on’ practitioner. Rolling herdaverage is 21,000 lbs. on 3X milking.

Tom Thompson: Tom is managing partner of StotzDairy, a 1,400-cow dairy in Buckeye, Arizona. Thefarm raises all its own replacements and has 1,500head of young stock. There are 17 employees. Thefarm hires a nutritionist to formulate rations and hasa veterinarian do fertility work at three-week inter-vals. The climate is hot and arid and cows are housedin drylot corrals. Milking is done 3X in a 34-stall poly-gon. Land base is 1,200 acres, some of which is usedto grow corn silage, oatlage, barley and alfalfa for thedairy. Stotz Dairy has had the top DHIA rolling herdaverage in Arizona for 8 of the past 10 years; currentherd average is 26,423 lb of 3.5% FCM.

How long have you been using BST?

Escobar: Escobar Dairy began using BST in Octo-ber of 1990. We were the first commercial dairy inMexico to use the product. We began by runningour own trial, with 70 control and 70 BST-treatedcows in a single pen. On that initial group of cows,we had a 15.3 lbs. increase in milk production. Thenwe began to use BST at 160 DIM (days in milk) onall bred cows with a body condition score of 3.5.Now, we begin BST injections on all healthy cowsat 100 DIM, with condition scores of 3.0 or higher,without regard to reproductive status.

St. John: Alliance Dairies began using BST abouttwo weeks after FDA approval was granted. We areassociated with two other dairies, one of which wasa trial herd, and we were convinced that AllianceDairy would benefit from utilization. Forty percentof the herd was treated initially. The use of BST wasapproached conservatively because of concern overpossible increased twinning rate. Presently, BST isused on all cows beginning at 120 DIM, exceptcows slated for culling, who begin receiving BST assoon after calving as they begin regaining body con-dition. Injections are given in lockups.


Making BST Work: The Producer Experience

Thompson: A trial with the Monsanto product wasconducted on Stotz dairy (100 injected and 100 con-trol cows) during the summer of 1989. The objec-tive was to determine if a response would be seenin heat-stressed cows, who at that time were beingmilked 4 times per day. We postponed using BSTafter FDA approval until mid-April, out of deferenceto our milk co-op which had asked producers toobserve an extended moratorium. Initially, we gavecows BST if they were greater than 100 DIM, exceptfor any cows who had disease problems or wereslow milkers. Now, we start cows at 60 DIM as longas their body condition score is 2.75 or higher. By100 DIM, nearly all cows are being injected.

What milk production response haveyou seen with the use of BST? How

was that response monitored?

Escobar: As I said, we demonstrated a responseof 15.3 lb (7 kg) in our initial farm trial. Since thenwe have not made an effort to track individual cowresponse to BST. Many things affect milk produc-tion, especially weather and feed quality. However,our herd average has increased from 19,820 lbs. to24,240 lbs. since October of 1990.

St. John: With 40% of the herd treated initially,we saw an increase of 4 lbs./day in bulk tank milk,indicating a 10-lbs. response in treated cows. It’s dif-ficult to evaluate the milk production response ona bulk tank or even an individual cow basis becauseof so many variables. This year we are actually ship-ping less milk than at the same time last year, butthis fall and winter have been harder on cowsbecause of wet and muddy conditions. We are con-fident that we are getting a response because of theincrease in bulk milk that occurs with each injec-tion. Our time is better spent on other aspects ofmanagement, such as improving heat detection orcow comfort, than on monitoring response to BST.

Thompson: In the mid-summer trial run by Mon-santo we observed an 8.6 lbs. increase in milk10.8%) with no difference in milk fat or protein; anincrease in SCC of 51,000; and no effect on repro-duction or metabolic disease incidence. Since this

trial demonstrated that the product was effective onour farm, we don’t feel the need to monitor responseclosely. Individual cow measurements on a day-to-day basis are probably not justifiable economically.When we started BST injections in April of 1994,we had a 7 lbs. increase in bulk milk within oneweek, with 52% of the herd getting injections. Thisindicates that injected cows increased milk pro-duction by about 13 lbs. We did not observe anincrease in bulk tank SCC.

Did you make any changes inthe feeding program prior to

beginning the use of BST?

Escobar: At the time we began using BST, we madeno changes in the feeding program. We were group-ing cows into three groups by production. We soonobserved that treated cows were losing body condi-tion. The diet already contained whole cottonseed,but we began adding additional tallow and protectedfat. We also began incorporating blood meal into theTMR. Since beginning the use of BST, we have hadto work harder to keep body condition on the cows.For instance, getting the best quality forage is criti-cal. Because cows are fed in groups, it’s difficult todetermine how much of an effect BST has had onfeed intake. Many other factors affect feed intake; lastsummer, for example, we had 60 days in a row withtemperatures over 1000F. For the same reason, it’s dif-ficult to measure the effect on feed costs.

St. John: Initially we made no changes in ourfeeding program. We feed a TMR to meet cows’appetite. Our nutritionist balances the rations forenergy and undegradable protein according to NRCrecommendations. We have always included sometallow in our rations. This past summer we alsoincluded a bypass fat source because cows’ bodycondition scores were lower than the previous year.We can’t really measure any increase in feed con-sumption and didn’t notice any appreciable increasein feed costs with BST use. Obviously, the cows willeat more feed if they’re making more milk, but feedintake is affected by a lot of other things (mostnotably the weather).


Thompson: We increased the energy density ofour TMR with additional bypass fat and tallow evenbefore we began using BST. We wanted to increasecows’ condition scores so they would have thereserves to respond to the injections. We haveincreased the undegradable protein in our rations,but that was more in response to our nutritionist’srecommendations than because we were using BST.We also switched to a true TMR, with hay blendedinto the ration rather than fed separately, for thesame reason. We observed an increase in feedintake of 4-6% about one week after the 2nd injec-tion, or three weeks into BST supplementation. Wecalculate that feed costs increased about 35¢ percow per day, or 43¢ per hundredweight of milk.

Have you noted any injection siteproblems (swelling or abscesses) withthe product? Do cows have a strong

aversion to the injections?

Escobar: We haven’t had any problems at theinjection site, but I feel this is due to careful train-ing of the person giving injections. Our personnelhaven’t noted any changes in the cows’ behavior.

St. John: We haven’t noted any significant injec-tion site problems. However, the cows seem to an-ticipate the injections. For some reason when youstrap on that red pouch, some cows become realidiots.

Thompson: We hadn’t noted any injection siteproblems until the veterinarian TB-tested the herd.Some cows had swellings which might have beeninterpreted as positive TB tests if we hadn’t notedthem beforehand. We have had to train the personwho does the injections to be sure that the cow getsthe entire dose and that it goes in the right location.The cows that are being injected tend to be appre-hensive when they are approached by a person theyassociate with needles. The vet knows which cowsare being injected.

Have you noted any changes inreproductive performance since

beginning the use of BST?

Escobar: We found that we had to increase theintensity of our reproductive management, particu-larly heat detection. We began routinely chalkingtailheads at that time. Once we made adjustmentsin the rations, reproductive performance also im-proved. We currently begin breeding cows A.I. at45 DIM, as long as they have healthy reproductivetracts. The cows are bred at least twice to a sire cho-sen by Holstein’s mating program, then we maybreed to less expensive sires. We do not use naturalservice. Calving interval is 13.4 months.

St. John: Calving interval is actually slightly lowernow than before we began using BST (presently 13.4months). However, we wait until 120 DIM beforebeginning injections, so most cows are already bred.We typically use A.I. for breeding up until 120 DIMand then use clean-up bulls.

Thompson: We have detected no change in re-productive performance at all and have made nochanges in our reproductive management. Our aver-age DIM at first breeding is 92 days. Our calvinginterval is 13.5 months and we feel this is the mosteconomical at this level of production. Cows are bredA.I. until we decide on an individual cow basis thatit’s time to use a clean-up bull. Treat every cow as ifshe’s your only cow and you’ll be profitable. On theother hand, our days open have actually increasedbecause cows who are identified as culls are remain-ing profitable and are staying around longer.

In your opinion, did the use ofBST make heat stress management

more difficult?

Escobar: We have not noted that heat stressaffects the cows’ response to BST. However, becausefeed intake is hurt by hot weather, it is more difficultto keep body condition on the cows during the sum-mer. We have found that we need to pay more atten-tion to cows’ body condition with the use of BST.

St. John: In the trial herd that I was associatedwith, we saw an 18% increase in milk productionwith BST in spite of high temperatures. I don’t be-lieve that BST increases a cow’s susceptibility to heatstress any more than high milk production does. We

Making BST Work: The Producer Experience


have what we consider “state of the art” facilities forminimizing heat stress: misters under pressure, sprin-klers, shade and fans. Cow comfort is very impor-tant to us, whether we’re using BST or not.

Thompson: We already had an extensive coolingsystem in place at the time we began using BST. Wehave a herd of high-producing cows and we wantthem to continue producing at high levels, regardlessof weather conditions. That situation didn’t changewith the addition of BST to our management system.

In addition to the labor required forinjections, have you tracked any otherlabor costs which might be attributed

to the use of BST?

Escobar: We have not incurred any increase inlabor costs due to the injections. The cows areinjected in lock-ups and we do a group of cows eachday. The cows are body condition scored with each“event”, such as calving, fresh cow exam, and BSTinjection. We are basically doing the job with thesame people as before BST. The same is true of feed-ing and milking.

St. John: The labor required to inject 1,000 cowsis 22.5 hours (or 45 hrs./month) including the timeto assemble syringes. There haven’t been any mea-surable effects on labor necessary for milking orfeeding; we milk 24 hours/day anyway and the milk-ers complete milking on schedule.

Thompson: One person does all the injections in6 hours (about 800 cows). A separate person iden-tifies cows to be injected. We put neckchains oncows at freshening and take them off when it’s timeto begin injections. Labor costs about 2¢ per cowper day to both identify cows and inject them. Thisdoes not include assembling the syringes, which

requires a significant amount of time. We haven’tnoted any significant increase in labor costs. Eventhe time to do the injections has been made by re-allocating other jobs. Time for milking and feedingis not really different.

What other observations haveyou made relative to the use ofBST that would be of interest

to other dairy producers?

Escobar: In many ways, using BST is like chang-ing from 2X to 3X milking. It’s important that youare managing the cows well before using BST,because management will be more difficult after-wards. Try to anticipate problems, like loss of bodycondition in cows or difficulty in detecting heats.Attention to detail, such as forage quality and cowcomfort, will be even more critical when using thistechnology.

St. John: If you look around the country, you seethat the producers who are successful are those whoproduce at the lowest cost. BST is a tool that can beused to cut the costs of producing milk. We candemonstrate that BST has made a significant differ-ence in our bottom line.

Thompson: The trick to using BST successfully isto reduce stress on the cows, to have everything elseright first. You have to be able to manage body con-dition so that cows will maintain response from yearto year. The real fallout from the use of BST will showup in the second year if cows aren’t fed properly.You need to make use of competent consultants whoare committed to your success. The beauty of thismanagement tool is that it can be turned on and offif milk or feed prices make it uneconomical.


notes


Footwarts In Dairy Cattle: Current

Understanding Of A Complex Disease

ur ing the last 7-8 years, footwarts has emerged as a serious cause of lameness in cattle in the Western United States. Reports

in the scientific literature reveal that footwarts occurs worldwide and has been known to have existed for more than 20 years, The first published report on footwarts was by DE. Cheli and Mortellaro in Italy in 1972. Additional reports from several other Euro- pean countries soon followed. Footwarts has also been described in Israel, Iran, Japan, Mexico and South America. This disease has been recognized in the United States for at least 15 years, with out-

major problem for dairies in other Western states. It is extremely unlikely that a footwart problem of the magnitude that exists today would have gone unrec- ognized for any appreciable length of time, indicating that this truly is an emerging problem. It is possible, however, that footwarts have been present

in the Western United States for some time but at a much lower incidence. Indeed, some hooftrimmers report seeing foot conditions identical to today's footwarts on California dairies as long as 25 years ago. This scenario would suggest that something has changed in the last 7-8 years to account for the dramatic increase in the

incidence of footwarts. One of the most perplexing questions is the

worldwide increase of this disease in the last few years. Although footwarts has been recognized in some parts of the world for more than 20 years, it seems that the same dramatic increase we are experiencing in the Western United States is happening worldwide. The increasing importance of the footwart problem was evidenced by the amount Of attention it received at the most recent International Symposium on Disorders of the Ruminant Digit held in Banff, Canada, in June 1994. Footwarts has gone from being an occasional nuisance to a substantial economic and health problem in dairy cattle worldwide. Given the various breeds of cattle,

breaks on New York dairies reported as early as the late-1 970s.

It is unclear when the problem with footwarts first occurred in the Western United States. Reports from dairy managers and hooftrimmers in California suggest that footwarts only recently became a significant problem in California and that prior to the late 1980s they were an insignificant problem or nonexistent. A recent survey of California dairies revealed that, today, approximately 75% of the dairies in southern and central California have experienced footwart problems. It also was estimated that approximately 8% of the cattle in these areas had footwarts during 1993. Footwarts has also become a

genetic differences, environmental conditions, nutritional factors and variations in overall dairy management practiced worldwide, it is hard to believe that a common event has occurred on a global basis to account for the worldwide increase in the incidence of this disease.

To fully understand the footwarts problem and develop appropriate control or prevention strategies, a clear definition of footwarts and differentiation from similar conditions is paramount. Footwarts is a superficial skin diseaseof cattle, which for the most part is limited to the area below, or at, the pastern. It involves predominantly the epidermal layer of skin with a lesser involvement of the dermal layer. The name footwarts became popular because of the superficial resemblance to true bovine viral warts. The majority of footwarts are located on the back 01 the foot between the bulbs of the heel and often involve the interdigital ridge. Less frequently, footwarts can be found on the plantar pastern, at the front of the foot or extending into the interdigital space. In some dairy cows the front of the foot seems

be a frequently affected site. Generally, the back feet are affected more frequently than the front feet. More than one foot can be affected at a time and occasionally multiple footwarts can be found on one foot.

The appearance of a footwart can be quite variable. Early footwarts tend to be flat, circular and have a fairly welldelineated border. Some footwarts are oval or U-shaped. They may be gray-to-red in color, appear moist and bleed easily when manipulated. As the lesion becomes more chronic, the footwart tends to become more proliferative in nature and may develop small, hair-like structures or fronds. These hair-like structures, in fact, represent abnormal skin growth. At the edge of some footwarts, true hairs can become quite long. The more mature form of footwarts is often elevated and can be golf-ball to tennis-ball size. They mayor may not have these long hair-like structures. The mature forms with the hair-like structures account for the commonly used term "hairy footwarts."

Confusing terms for footwarts, and an incomplete understanding of the various ways that footwarts can present, has led to a great deal of confusion about footwarts. There are many lay and scientific terms that have been applied to this disease, which attest to the confusion that has existed. lay terms such as hairy footwarts, strawberry heel, raspberry heel and heel warts, in fact, all refer to the same condition. In the scientific literature, the number of terms used to describe the same disease has been just as confusing with names like interdigtital papillomatosis, digital dermatitis, and verrucous dermatitis and papillomatous digital dermatitis all being used for the same disease. In the past, some of these terms were used to describe what were believed to be entirely different conditions. We now know that these different terms merely describe different stages, or presentations, of the same condition. At the recent meeting of international workers on disorders of the ruminant digit, many individuals from around the world currently working on footwarts were in atten- dance. Jointly they were able to help clarify the footwart terminology problem. The meeting also resulted in establishment of an international task force aimed at maximizing dissemination of new information about this disease.

Just as important as recognizing what constitutes a footwart is the ability to recognize what a footwart is "not." Numerous other foot conditions that can affect cattle must be differentiated from true footwarts. Footrot is a common foot condition that can be differentiated readily from footwarts by the presence of swelling of the foot and separation of the toes. These signs are not present in uncomplicated cases of footwarts. Sole ulcers, pastern ulcers, laminitis, white line disease, fibromas (corns), heel ero- sions and interdigital dermatitis are other foot conditions that may also be encountered. Close examination of the foot is necessary to identify and differentiated the many foot conditions of cattle. As our knowledge about footwarts has increased, the full spectrum of ways in which footwarts can present continues to expand. Some researchers have inde- pendently suggested that interdigital dermatitis may,

in fact, be another manifestation of footwarts, dif- fering only by the location of the lesion. Therefore, when trying to assess accurately the seriousness of footwarts disease on a dairy, it is important that all possible causes of lameness be considered. Keep in mind that two or more foot problems may exist on a dairy at any one time and that an individual cow may have two or more foot-related problems simultaneously.

Usually, the first sign that brings one's attention to the possibility of footwarts is an increased number of lame cows. On some dairies, it is predominantly the heifers that are affected; others report a more even distribution of ages affected. Although, footwarts can cause moderate-to-severe lameness, not all cattle affected with footwarts have detectable lameness. It some cases, an abnormal stance may be the only sign exhibited. We have visited some dairies where the dairy owners and managers have stated, with certainty, that no problem with footwarts existed. However, upon examination of the feet of cows as they passed through the milking parlor, footwarts were found. This illustrates how the problem can be present, but missed, when only a limited number of cows are affected or if the lameness is subtle in nature. Lameness should not be used as the sole criteria for determining if footwarts exist on any particular dairy. To properly determined if a dairy has a footwart problem the feet of sound cows, as well as lame cows, should be examined. If hooftrimmers are employed for routine hoof maintenance, they can serve as an ideal source for accurately assessing footwarts and the magnitude of the problem.

The severity of a footwart problem on a dairy can be quite variable. On some dairies, only a small number of animals are affected. Under these cir- cumstances, the situation does not present a serious health or economic problem. Other dairies experience explosive outbreaks with numerous animals affected over a short period of time. Still other dairies may experience persistent problems with a substantial number of cattle affected at any one time. In the last two scenarios, the economic impact can

be quite substantial. Lameness can cause weight loss, decreased milk production and decreased fertility. Understanding the factors on the dairy, that may predispose to the development of footwarts are critical in developing programs to control the numbers of cases of footwarts, thereby minimizing the economic impact.

A main goal of the Footwart Task Force at the School of Veterinary Medicine at the University of California, Davis is to identify factors important in the control of footwarts. Most information about potential factors associated with footwarts is based on individual impressions; few controlled studies have been conducted. With funding support from the California Dairy Foods Research Center and the UCD School of Veterinary Medicine Livestock Dis- ease Research Laboratory, the task force is trying to establish the environmental factors that predispose dairy cows to developing footwarts and the differences that account for one dairy having severe footwart problems while others only have occasional problems. Some preliminary findings from a study conducted by Dr. David Hird indicate that the combination of wet and warm weather predispose to serious footwarts problems. In southern California, although footwarts can be a year-round problem, most cases occur in late spring and early summer when fair amount of moisture is present and the temperature is rising. The muddiness of corrals has also been found to be a important factor and may be a reflection of overall corral management rather than just degree of muddiness. Other factors such as abra- siveness of the footing surface and confinement are also likely to be important. Dairies that maintain cows on pastures, rather than in dry lots or freestalls seem to have lesser problems with footwarts.

The exact cause of footwarts remains a mystery. Most researchers believe it is multifactorial in nature and that all factors must be in place for the disease to develop. Footwarts can rapidly spread on a dairy once it is introduced which suggests that an infectious component is involved. initially it was believed that viruses play a role because of superficial similarities of footwarts to true bovine warts, which are

caused by a papilloma virus. Searches for possible viral agents have been conducted by several individuals using a variety of techniques, including elec- tron microscopy, immunoperoxidase tests and DNA probes. All of these studies have failed to detect viruses associated with footwarts.

The observation that footwart lesions often resolve, or greatly decrease in size, when antibiotics are given by injection, without manipulation of the footwart itself, was essential in identifying an important factor. Since antibiotics are active only against bacteria, and not viruses, the response of footwart lesions to antibiotics strongly suggests that bacteria play a important role in the disease. The same results are also obtained when antibiotics are applied top ically to the footwarts itself, especially if the lesions are in the early stages. In these cases, pain and lameness often disappears within 24-48 hours. It is unclear whether the role that the bacteria play is a primary role or whether it is only after some other initiating factor(s) that bacteria become important.

to treatment with Injectable

force. Our first goal has been to isolate them in the laboratory. Once isolated, a criteria for classifying them must be developed. To date, we have isolated two types of spirochetes and are currently studying which one is invasive in the footwarts. It does not appear that either of these bacteria has been isolated previously. We are also conducting a more comprehensive study to identify the other bacteria found in footwarts. This has proved to be difficult, since many of these organisms have never been previously identified.

Based on current knowledge, there are treatment and control measures that can be undertaken for footwarts. Because each dairy is different, it is important that approaches for control and treatment of footwarts be customized to the particular situation. First, it is important to establish that footwarts exist on the dairy and, if present, to establish the magnitude of the disease problem. A biopsy of a lesion is useful for initial confirmation of footwarts.

If a dairy is truly free of footwarts, then efforts to prevent introduction are extremely important Based on the premise that there is an infectious component to footwarts, and since the specific agents are yet to be identified with certainty, standard biose- curity procedures should be employed. Maintain- ing a closed herd is the best way to prevent introduction of footwarts. If replacement heifers must be purchased from an outside source, the replacement heifers should be quarantined for at least one month and all feet closely examined for active footwarts before allowing these animals to mix with the herd. Prophylactic treatment, such as footbaths, may also be beneficial for minimizing potential for introduction. individuals who perform services for the dairy, such as hooftrimmers and veterinarians, should be requested to disinfect boots and equipment prior to working with COWS on the dairy.

In infected herds, topical treatments with antibiotics or caustic compounds, applied either in footbaths, by sprays or by footwrap have been shown to be effective in treating footwarts. In a recent controlled clinical trial headed by task force member Dr. Walter Guterbock, topical tetracycline or linco-

In an experimental trial that we conducted, material from active footwart lesions was applied to the feet of unaffected cattle. NO footwarts developed. Even the presence of skin abrasions did not lead to the development of footwarts. These findings suggest that mere exposure to footwart material and the associated bacteria is insufficient to cause footwarts. This finding supports the suspicion that other factors must also be present for footwarts to develop. It is hoped that studies to identify factors on dairies with severe footwart problems will provide clues.

Since bacteria do appear to play an important role in the disease process, the task force has been attempting to determined which bacteria are associated with footwarts and which bacteria may be important in the disease process. The environment in which cattle spend most of their time obviously lends itself to exposure to numerous types of bacteria. The main problem is to determine which of these bacteria are important. Using a special staining technique, Dr. Deryck Read showed that a large number of spiral-shaped bacteria could be found fairly deep in the footwarts. These particular bacteria, called spirochetes, have been a focus of the task

mycin/spectinomycin footwraps were shown to be highly effective treatments. Both of these treatments resulted in greater than 92% recovery. Most researchers feel that lincomycin is the active component in the lincomycidspectinomycin combination. Because lincomycin can be toxic or lethal to cows if taken orally, great care should be taken to ensure that it is not ingested. Intramuscular injections with ceftiofur or topical application of formaldehyde were also effective, but less so than the antibiotic footwrap treatments.

The effectiveness of topical antibiotic treatments is most likely due to the superficial nature of the infection. Since footwarts are superficial in nature, deep penetration of topical antibiotics is not required be effective. To maximize the effectiveness of topical treatment, lesions must be treated in the early or intermediate stages, and the lesion must be adequately cleaned prior to the antibiotic treatment. Many of the failures reported with antibiotic treatments can be traced back to inadequate foot preparation prior to treatment. Once the footwart becomes mature and proliferative in nature, surgical excision may be required to effect a cure. The entire footwart must be removed rather than just shaving off the top portion of the footwart. Secondary infections can result as a complication from surgical removal of the footwart.

Footbaths have an overall role in maintaining hoof health and can be used in conjunction with other measures to control footwarts. When used as the sole method of treatment, results have been variable and sometimes have been only minimally effective. As with any topical treatment, adequate cleaning of fecal material from the hoof, especially material that may be covering the footwart, is very important prior to using a footbath. To obtain maximum benefit from any footbath, it is also important to maintain footbaths at proper levels to ensure that the entire hoof and pastern area is submerged to adequate level. Regular changing of the footbaths, to minimizing the amount of organic contamination, is also critical.

Documented information on the efficacy of par-

ticular compounds used in footbaths is lacking. Some of the variable responses reported for footbath use are most likely due to lack of attention paid to maintaining proper footbath conditions. A variety of types of footbaths have been used with variable success. Most individuals report that copper sulfate footbaths are not effective in the treatment of footwarts. Copper sulfate with a pH adjustment has been reported to be more effective than copper sulfate alone but not as a sole treatment. Formaldehyde (3- 5%') appears to be effective for some individuals, whereas others have reported little or no success. Too strong of a concentration of formaldehyde can cause destruction of healthy hoof tissue or can even lead to sloughing of the hoof. Some individuals also report that the bacterial action of the lagoons slowed noticeably after using formaldehyde in footbaths. In addition, there is concern for worker safety when formaldehyde is used. Preventing accidental exposure to the formaldehyde is important. Tetracycline footbaths have been used by a many individuals and appear to be effective when used properly. Failure when using tetracycline footbaths are probably due to inadequate footbath levels and organic contamination. The use of tetracycline footbaths as a sole treatment appears to be better suited to small, rather than large, dairies. In some cases, footbaths may play a bigger role in prevention and control rather than as an actual treatment for active footwarts.

It is important to be aware that most of the current treatments for footwarts are being used in an "off-label" manner, that is to say that these compounds are not specifically approved for this type of use. It is, therefore, strongly recommended that footwart treatment and control efforts be incorpo- rated in an overall herd health program and that treatment and control efforts be discussed with and monitored by a veterinarian to prevent problems with residues.

The use of vaccines to control footwarts is an area of great interest. Since the exact agent(s) responsible for footwarts still m a i n to be proven conclusively, it is somewhat premature to consider using vaccines for either prevention or treatment of foot-

warts. Anecdotal information about interdigital dermatitis vaccines to treat or prevent footwarts have been equivocable. Even after the particular agent(s) associated with footwarts have been conclusively identified, there is some question as to how effective a vaccine would actually be. Cows with natural infections do not appear to develop a sustainable immunity to reinfection. The superficial nature of the infection may also complicate development of an effective vaccine.

A great deal of information about footwarts has been learned in a relatively short period of time, in large part due to the cooperation of dairy owners, hooftrimmers and veterinarians. It is apparent that footwarts is a more complex problem than it appears to be on superficial examination. We still have far to go. However, through continuing research efforts, it is hoped that more effective treatment and control measures will be available in the not-too-distant future.

Colostral Management: How Good Is

Your Program?

t birth, the baby calf is highly susceptibleto oglobulin but need to recognize that it does more. disease and has been provided with very immunoglobulins (also known as antibodies or A meager nutritional reserves. The dam's col- gamma globulins) are proteins that the body man-

ostrum specifically provides elements that enhance ufactures to attach to invading organisms and neu- the calf's disease defenses and supplement other tralize them. Specific immunoglobulin (Ig) will nutritional needs. Therefore, colostrum can be therefore be manufactured against specific organ- viewed as the single most important nutritional fac- isms. The process Of passive transfer Of lg involves tor for the newborn calf and management practices the secretion of lg by the dam into the colostrum, that enhance the appropriate supplementation of the consumption of the colostrum bv the newborn colostrum to newborn calves are critical for increas- calf, and subsequently the absorption of the lg ing calf survival. The focus of this talk will beon fac- through the intestinal wall and into the calf's circu- tors that influence colostral quality and colostral lation. The absorbed immunoglobulins protect the management practices that support the health of the calf against systemic invasion by microorganisms, newborn calf. thus are a critically important aspect of the calf's

Immune Defenses Of The Newborn Calf immune defense system. The mammalian system of defense against inva- It is important to realize that passive immuno-

sion by disease-causing organisms has multiple globulin transfer is not a simple "yes" or "no" equa- components. Chief among these are: tion. Acquisition of lg does not guarantee the calf a

1 ) humoral immunity, which is provided by cir- disease-free future. To protect the Calf against dis- culating and local tissue immunoglobulins; ease, the immunoglobulin has to be present at the 2) cellular immunity provided by certain subsets right place where the organism is invading, must be

of lymphocytes; present in sufficient quantity to neutralize the agent, 3) other white blood cells including neutrophils and must be Of the appropriate immunoglobulin

and macrophages; and type to attach to the specific invading organism. 4) other defense proteins including complement, Whether a calf remains healthy or develops disease

kinin, and other inflammatory proteins. Compared will depend on the balance between disease expo- with older animals, the newborn calf is unique b e sure versus disease defenses. AS mentioned above, cause it has not previously encountered disease other nonimmunoglobulin defenses are also impor- organisms and its immune system is functional but tant for the calf's disease prevention. Nevertheless, has not had the "experience" of recognizing spe- a very strong association between passive lg trans- cific disease agents. Further, the bovine placenta fer and calf disease resistance has been shown * does not allow the passive transfer of protective peatedly and this process must be seen as the sin- immunoglobulins to the calf. As a result, the new- gle most important factor that we can manage to born calf relies on colostral consumption to prime enhance calf health. its immune system with elements made by its more Because Circulating lg is effective in preventing experienced dam. microorganism invasion, passive lg transfer is pri-

The aspect of colostral immune protection that marily responsible for preventing septicemic bacte- has been most thoroughly described pertains to its rial infections. Absorbed immunoglobulin is not content of immunoglobulin. It is clear that colostrum nearly as effective at preventing localized enteritis has elements that enhance the other immune func- (neonatal calf scours). Agents such as rotavirus, cor- tions listed above but the importance and specific onavirus, and Cryptosporidia only affect the Super- actions of these other mechanisms have not been ficial lining of the gut wall and it appearsthat circu- thoroughly researched. Therefore we look at col- lating lg has limited efficacy in preventing this type ostrum as providing critically important im-mun- of infection. Numerous studies suggest, however,

that the severity of diarrhea in enteric disease of neonatal calves and the ability of affected calves to survive is positively influenced by increased circulating Ig. Although passively acquired Ig cannot prevent all calf diseases, virtually all studies of neonatal calf performance show a positive benefit of increased Ig transfer on calf health and survival.

Factors Involved In Passive Transfer A number of techniques are available for mea-

suring the efficacy of passive Ig transfer to calves. All of these techniques involve the measurement of protein in plasma or serum. Some of these techniques (refractometric protein measurement, zinc sulfate turbidity and sodium sulfite turbidity) are quite inexpensive and can be performed at the farm. Using such measurements, we have developed a good understanding of the factors that positively influence passive Ig transfer.

The two most important factors in passive Ig transfer are the total immunoglobulin mass that is ingested, and the time after birth when the colostrum is received. The immunoglobulin mass is a combination of Ig concentration in the colostrum and the amount of colostrum fed. The product of these two factors is the total immunoglobulin available for absorption by the calf's intestine.

The volume of colostrum produced by a cow is generally not a limiting factor in dairy operations, although it may be a concern in some beef management situations. The volume of colostrum consumed, however, determines the amount available for absorption and this isdetermined by the amount the calf suckles or is fed. Some producers let the calf suckle the dam, and it might be expected that this would be an efficient method. Although some studies have shown that natural suckling enhances calf

Ig absorption, this method of feeding can also be associated with a significant rate of failure of passive transfer. Factors that contribute to this failure include poor mothering ability by the dam, dam sickness at parturition, poor udder conformation and/or teat structure, and poor calf viability or sucking ability. All of these factors can lead to inadequate voluntary consumption by the calf. It is noteworthy that dairy calves have less vigor and poorer suckling drive than their beef calf counterparts where this method of colostral consumption is the norm.

Colostral immunoglobulin concentration can vary tremendously between cows. Older cows generally produce higher quality colostrum than heifers, but there is also wide variation between individuals, even in multiparous cows. The immunoglobulin concentration of colostrum can be estimated by measuring its specific gravity and a commercially device is available for this purpose. This colostrometer can be valuable in helping select the cows from which colostrum is fed to the newborn calf. Varia- tions in first milking immunoglobulin concentration can easily range from 20-80 mg/ml or a four-fold difference.

Recommendations for the minimum immunoglobulin mass that a newborn calf should receive are about 100 gm of immunoglobulin. A more appropriate aim would be to provide between 200- 300 grams; thus, 4 liters of colostrum at 50 mg/ml would provide 200 gm immunoglobulin to the newborn calf, well in excess of the suggested minimum.

The time at which colostrum is fed to the newborn calf is also very important. It has been well established that immunoglobulins are absorbed from the intestine for only the first 24-36 hours after birth. All studies agree, however, that there is a substantial decline in the capacity of the intestine to absorb Ig throughout this time. The earlier the calf receives an appropriate amount of immunoglobulin, the better the absorption will be. The recommendation must be that colostrum is fed as soon as possible after birth and preferably within the first two hours of life. Delaying the first colostral feeding beyond six hours of life has been shown todecrease

the efficiency of immunoglobulin absorption and increase the calf's susceptibility to disease.

The method of feeding colostrum to calves has also been investigated. These studies suggest that suckled colostrum provides better passive transfer to the calf. In many cases, however, this is impractical and it is frequently better to ensure colostral ingestion than to wait until the calf consumes the colostrum by nipple feeder. While suckling the colostrum from the teat of the dam may theoretically provide the calf with the most efficient absorption, it can also delay the time of first feeding and reduce the total volume consumed. These factors likely account for the high rate of failure of passive transfer seen in many dairies that practice this a p proach to colostral management. Feeding colostrum via nipple feeder is a good alternative, but for calves with weak suckle reflex it may require inordinate amounts of time. Although small family farms may have workers with the interest in ensuring colostral intake by this method, time constraints may limit the success of nipple feeding in larger enterprises. Ad- ministration of colostrum by an esophageal feeder will introduce the colostrum into the rumen rather than the abomasum. When sufficient volume is provided, however, the majority will pass rapidly into the abomasum and ensure adequate absorption, even though the efficiency of absorption may be slightly impaired.

Management Of Colostral Feeding The issues discussed above suggest some practi-

cal guidelines for the management of colostral supplementation to calves. Knowing that immunoglobulin absorption is critical to optimal calf health and knowing the factors that are most influential in passive Ig transfer provides some simple guidelines for colostral feeding. Because most of the information presented above has been known for years, the most remarkable finding is the small number of dairies that monitor colostral quality, manage colostral feeding effectively and subsequently monitor passive transfer in their calves. Failure to adopt such colostral management guidelines is reflected in the recent National Animal Health Monitoring System survey

of dairy heifer calves, which showed that over 40% of the calves monitored on dairy farms across the country had serum IC levels below 1,000 mg/dl. Over 27% of the calves tested had levels below 620 mgldl, which was the lowest level measurable with the testing procedure used. If we assume greater than 2,000 mg/dl of circulating serum IgG is an acceptable level of passive Ig transfer, then 67% of the calves sampled had inadequate circulating levels. As testimony to the importance of this measurement, mortality rates in calves with less than 1,000 mg/dl were two-fold greater than in calves with higher levels of circulating IgG.

A reasonable understanding of the calf disease equation suggests that there is no absolute level of circulating IgG that will ensure calf health. Likewise, there is no single recommendation for colostral management that will ensure appropriate passive

transfer in all calves. At a minimum, however, we can apply some simple guidelines. A list of suggested guidelines for colostral management is provided at the end of this text. Given the information described briefly above, it is reasonable to provide calves with a minimum of 2 liters of colostrum within two hours of birth, followed by an additional 2 liters fed within 12 hours of birth. Such colostrum should at a minimum have an Ig concentration of 30 mg/ml, although 40-50 mg/ml would clearly be moredesirable. Because older cows have more disease experience and provide more concentrated Ig levels in their first milking colostrum, the older animals should be selected as colostral donors for newborn calves. The variation in Ig concentration of colostrum from even aged cows means that a screen- ing of donors with a colostrometer can be effective in excluding low Ig producers from the donor group.

Freezing maintains the quality of colostrum for providing Ig transfer to newborn calves. Therefore, the highest quality colostrum can be identified and frozen for future use as the first feed for later newborn calves.

The calves at highest risk of contracting neonatal disease are those from first calf heifers. In general, heifers will have the highest rates of dystocia and this in turn will reduce theviability of their offspring. Dystocia has far reaching effects on the well being of a calf, but included among its effects are a reduced suckle reflex and increased time to first standing. Under unmanaged or natural suckling conditions, this reduced viability contributes to a very high rate of failure of passive transfer in affected calves. In addition, the dam has poorer colostrum on average than her older herdmates, compounding the effects of delayed time to suckling and reduced volume of colostral consumption.

Although hand feeding via nipple may be the best artificial means of feeding the newborn calf, calves that fail to suckle within the first couple hours of life should be fed via esophageal intubation.

Monitoring the success of passive Ig transfer to newborn calves is a very important aspect of the colostral management program. Measuring calves' blood protein concentration can be easily and economically accomplished and should be routinely performed on a percentage of calves less than seven days old. Adjustments in the colostral program should beconsidered on the basis of these measurements. Equally important is a system to monitor calf health or disease problems. As discussed above, colostral transfer is very important but by no means the only factor influencing calf disease. A monitoring system that provides information on both colostral transfer and disease occurrence is invaluable in helping direct management changes to improve calf health. The herd veterinarian should be involved in diagnosis of specific disease problems. Some diseases, such as calf septicemia, can be very responsive to changes in colostral management. While others, such as calf scours, are less responsive to colostrum, and their control requires close

attention to other management features. Findings from the National Animal Health Monitoring Sys- tems survey highlight this important aspect of calf health problems. As mentioned above, mortality . rates are greater in calves with poor colostral transfer. Some calves will still get sick and die, however, even when Ig transfer has been highly successful. Data from this study suggests that approximately 30% of preweaned heifer-calf deaths could be prevented by ensuring all calves exceed 1,000 mg/dl of IgG at 24 to 48 hours. This also implies that a p proximately 70% of deaths would not be prevented through higher serum IgG. Nonimmunoglobulin Components Of Colostrum

It has already been mentioned that colostrum contains additional benefits for the newborn calf beyond the provision of immunoglobulin. Other factors that enhance immunity are also secreted into the colostrum. These include immune-acting cells and a variety of nonimmunoglobulin proteins. The degree of benefit that they provide the calf is unknown, and there are no practical methods at this time for their evaluation on farm.

The more standard nutritional elements are also present in far greater abundance in colostrum than in normal cows' milk. The total solids in colostrum are approximately double those found in milk. Fat percentage is approximately 50% increased, while protein content is more than quadrupled. The bulk of the increased protein is, of course, immunoglobulin but casein content is also double that found in milk. Lactose is the only major constituent of colostrum that is lower (approximately 50%) than the level in normal milk. Thus, while the newborn calf's body reserves are not extravagant, the feeding of colostrum provides the calf with an abundance of protein and energy.

Associated with the high levels of fat in colostrum, the fat soluble vitamins A, D and E are also present at 4-8 times normal milk levels. Vitamin B12 is available at an 8-fold higher concentration. The macro- minerals (calcium, phosphorus and magnesium) are at double to quadruple normal milk levels, while the micronutrients (e.g. copper, iron, zinc, cobalt)

Guidelines For Colostral Management Management of colostral supply:

Selection of donors. 1. Healthy dams with prolonged residence at the farm. 2. No precalving milking or milk loss. 3. Only first mllking colostrum should be used for the first 14 hours of life.

Monltor colostral quality with a colostrometer and exclude lower quality colostrum from the flrst feedings.

Maintain a frozen bank of high quality colostrum for use as needed.

Management of colostral feeding:

Feed a minimum of 5% of body weight (typically two quarts) at each colostral feeding. 1. Feed first within two hours of birth and again within 12 hours of birth. 2. Several methods of feeding are acceptable. 3. After the first two feedings, continue to feed colostrum from later milking and of lower quality for its nutritional value.

Monitoring the program:

On a routine, periodic basis (monthly), monitor calf health. 1. Incidence of specific diseases. 2. Age of dlsease onset. 3. Response to treatment. 4. Death rate. 5. Growth rate.

On a routine periodic basis (monthly), monitor blood of calves less than seven days old for Ig content.

are present at 5-20 times normal milk levels. Aside from its value as a source of immune enhancement, colostrum provides the calf with critically important nutrients.

Colostrum may be one of the most underutilized sources of dairy calf nutrition. Assuming that the average dairy cow produces between 40 and 50 kg of milk throughout the first six milkings, and that only 4-6 kg will be fed to the calf Over the first 24 hours of life, there should be an abundance of extra colostrum available for calf feeding over the first one to two weeks of life. If a colostral management pro-

gram is used whereby only first milking colostrum from mature cows is fed to newborn calves, then all heifer colostrum and aged cow colostrum from the second through sixth milkings could be made available as a source of nutrition. In many situations this may require the establishment of a colostrum storage pool. Numerous methods for pickling or fer- menting colostrum have been successfully devised, allowing the use of colostrum as a nutritional source. Because of the higher solids content of colostrum, smaller amounts can be used or the colostrum can be mixed with water and similar calf performance

can be achieved as with milk replacer or discard mastitic milk. The composition of colostrum can be fairly similar to normal milk as early as the fourth postpartum milking and many dairymen will begin to market the milk by this time. It should be noted that most dry cow mastitis treatments recommend a discard time of six milkings postpartum and attention to this factor may become more important as regulations on antibiotic residues in milk become more stringent with time. A good system for managing colostrum as a nutritional source for calves can be very important in the overall calf nutrition scheme.

Colostral Supplements There are presently several commercially avail-

able products marketed as colostral supplements. These products are formulated either by spray dry-

whey proteins available from the manufacture of cheese. These products can be marketed as immunoglobulin supplements if they demonstrate efficacy in providing passive Ig transfer and protecting the colostrum-deprived calf against infectious challenge. Generally the products areguaranteed to contain a minimum level of bovine-origin im-muno- globulin (e.g. 25 gm bovine Ig/package).

When mixed per label directions and fed to calves that are otherwise not provided a source of colostrum, these products will indeed improve the calf's chances of survival. On the other hand, the efficacy of these products to protect the calf against disease pales in comparison with natural first milking bovine colostrum. As mentioned earlier, the minimum total immunoglobulin mass recommended for administration to the newborn calf is 100 gm. To meet this level would require the feeding of three to four packages of the typical colostral supplement

product. Furthermore, recent evidence suggests that the efficiency of absorption of immunoglobulin by the calf from such products is substantially less than the efficiency of absorption from natural colostrum. This means that even if equal quantities of immunoglobulin are fed, the calf receiving a colostral sup plement product will absorb only one-third to one- quarter as much immunoglobulin as it would from colostrum. With these considerations and additionally the cost of colostral supplements, they are a very poor bargain. As the label suggests, these products are supplements, not substitutes. With the considerations described above, the dairyman will be much farther ahead to establish a good colostral management program than to try to make up for management deficiencies by purchasing colostral supplements.

In theevaluation of dairy calf nutrition, one of the most important areas is the provision of colostrum to the newborn calf. Colostrum provides not only high quality and high density nutrition in the conventional sense of energy, protein, vitamins, and minerals, but is also the single most important factor in the enhancement of neonatal calf immune defenses. A variety of factors are involved in the establishment of good passive immunoglobulin transfer to calves and most of these factors can be positively influenced by a good colostral management scheme. Despite increased knowledge about the importance of colostral management in dairy calf health, recent surveys show inadequate passive transfer in 40-65% of dairy calves with a resultant negative impact on dairy calf health and survival. The institution of good colostral management practices can have a substantial impact on overall calf performance.

ing dairy cow colostrum or by concentrating the summary:

RationalTreatment Of

Clinical Mastitis

By Walter M. Guterbock, DVM, MSVeterinary Medicine Teaching and

Research CenterUniversity of California, Davis

Tulare, CA 93274209-688-1731

fax 209-686-4231


MM astitis is the most common cause of anti-biotic use in adult dairy cows. In surveysof well-managed herds with somatic cell

counts (SCC) under 150,000/ml and virtually nomastitis due to coagulase-positive Staphylococcusaureus (Staph.) or Streptococcus agalactiae (Strep.ag.), 35-55% of lactations had one or more incidentsof clinical mastitis2,4,7,8,9. In such herds, 15-40% ofthe clinical cases had no bacteria isolated from themilk, 21-43% had coliforms, and 9-32% had envi-ronmental streptococci1,2,4,7. This contrasts with highSCC herds with a significant prevalence of Staph.and Strep. ag., where most of the clinical mastitis iscaused by those organisms4. As more herds respondto quality incentives and stricter SCC standards bycontrolling the contagious pathogens, we can ex-pect the relative importance of the environmentalpathogens to continue to increase.

The decision whether to treat clinical mastitis isan economic one, perhaps influenced by sentimentfor a given cow. The future economic value of thecow in the milking herd, which depends upon herage, conformation, past performance and presentreproductive status, must be considered. So mustthe costs and benefits of treatment, the value of dis-carded milk, the probability that treatment will fail,the likelihood of a relapse, the cow’s present valueas a cull, the availability of replacement animals,and the risk of errors causing antibiotic contamina-tion of milk or the carcass. The likelihood of a treat-ment failure or a relapse is higher for a cow that hashad previous unsuccessful mastitis treatments. Al-most all studies of clinical mastitis treatment focuson bacteriological cure. There is very little economicinformation available to dairymen to help themmake this daily decision.

Some dairymen and veterinarians have alreadydecided that the risks of antibiotic use in most clin-ical mastitis cases exceed the benefits and have stop-ped treating clinical mastitis cows with antibioticsin herds with a low prevalence of the contagiousorganisms. They emphasize protocols of frequentmilkout aided by oxytocin (OT) injections and anti-inflammatory drugs, along with heightened atten-

tion to management of housing, bedding and pre-milking hygiene to prevent infection with environ-mental pathogens. While the anecdotal reportsabout such programs are favorable, there is no pub-lished data about the rate of chronic or recurringinfections in such herds compared to herds usingantibiotics, nor on the effects of these infections onbulk tank SCC or subsequent milk yield.

Antibiotic Therapy Of Clinical MastitisTo date there has been no published evidence

that the economic benefits of antibiotic treatment ofmild clinical mastitis outweigh the risks and costs.We have found only one published study on intra-mammary antibiotic treatment of mastitis under fieldconditions that includes untreated controls. In thisabstract25 results of three treatments were reported.Treatments occurred over an eight-year period.Treatment A was 100,000 IU penicillin and 150 mgnovobiocin used twice. Treatment B was the samemedication used three times. Treatment C was 200mg of cephapirin used twice. Treatments A and Bwere used from 1979-85 and treatment C from1985-87. Group D were untreated controls, whichwere split into two groups contemporaneous withthe antibiotic-treated groups. No contagious path-ogens were reported. The abstract does not statewhether the treated quarters were clinically abnor-mal, and only bacterial cure rates are reported. Forenvironmental staphylococci, cure rates were62.9%, 70.4%, 67.3% and 0-7.3% for A, B, C andD, respectively. For environmental streptococci,cure rates were 50.2l%, 58.3%, 48.7% and 1.9-7.7%. For all coliforms, cure rates were 23.2%,13.0% and 7.9-13.4% for B, C and D. For Klebsiellasp., cure rates were 20.4%, 6.5% and 6.3-7.7% forB, C, and D. For E. coli alone, cure rates were40.9%, 25.9% and 20-47.7% for B, C and D. Sta-tistical tests of results were not reported, but groupnumbers ranged from 20-413. It would appear thatthese antibiotics were of benefit in the staphylo-coccal and streptococcal infections, and of marginalor no benefit in the coliform infections.

Intramammary infusion of pirlimycin, a lincosa-mide antibiotic, has been found to be effective as


Rational Treatment Of Clinical Mastitis

against clinical mastitis caused by gram-positiveorganisms in research sponsored by its developer26.These studies used both bacteriological cure andreturn of milk to normal as endpoints and includeduntreated controls. In an earlier study, 50 mg of pir-limycin (the dose in the commercially availableintramammary product) was found to cure 66.7%(16/24) of cases of experimentally-induced Staph.mastitis. This cure rate was significantly different forthat of untreated controls. Cure was defined asabsence of Staph. bacteria at 11, 14, 21 and 28 dayspost-treatment. Cows had both subclinical and clin-ical mastitis in this trial.

Chamings3 reported an 87% clinical cure rate incows that were not treated with antibiotics for mildclinical mastitis caused by Staph. and Streptococ-cus uberis. The bacteriological cure rate for bothorganisms was 19-20% This study did not have apositive control group for comparison. This type of

mastitis is treated on most dairies with mastitis tubes,possibly in conjunction with extralabel parenteralantibiotics or anti-inflammatory drugs. All of theapproved intramammary mastitis preparations onthe market in the United States as of November,1993, with the exception of pirlimycin, were testedagainst subclinical infections with gram-positiveorganisms. Only one has a label claim for mastitiscaused by E. coli, which is the most frequently iso-lated udder pathogen in many outbreaks of clinicalmastitis in herds with low SCC.

The pharmacology of mastitis therapy has re-cently been reviewed6,13,14. Reasons why antibiotictherapy might fail are summarized in Table 1. Mosttreatment studies focus on bacteriological cures. Yetsubclinical infections with environmental and con-tagious pathogens probably exist in every herd4.Clinical mastitis may be due to the flareup of sub-clinical infection in a stressed cow, and often signs


Table 1: Reasons For Failure Of Antibiotic Therapy Of Clinical Mastitis

A. Drug can not reach all sites of infection1. Microabscess formation (Staph.)2. Blockage of ducts with clots of denatured milk.3. Poor distribution of drug in udder due to swelling, edema or intrinsic properties of drug.4. Abscessation.5. Fibrosis.6. Intracellular bacteria (Staph.)

B. Bacteria already killed by cow’s immune system before therapy begins.C. Inadequate concentration of drug to effect killing.

1. Poor distribution of drug in udder.2. Absorption of drug from milk into systemic circulation.3. Failure of drug to be absorbed by affected tissues4. Drug milked out at subsequent milking.5. Failure of parenteral drug to cross blood-milk barrier6. Failure of client or veterinarian to repeat treatments in time to maintain MIC in tissue long enough toeffect killing.

D. Bacteria refractory to killing by drug.1. Bacteria not in rapid growth phase required for drug to act.2. Organism is resistant to usable antibiotics (e.g., Pseudomonas, Mycoplasma, yeasts, etc.)3. Drug with gram-positive spectrum used on gram-negative infection.4. Acquired resistance by organism.5. Emergence of L-forms, ‘naked’ acapsular forms that resist beta-lactam antibiotics.

E. Reinfection of affected quarter.

of clinical mastitis persist after bacteria can no longerbe isolated from the affected quarter. In the shortrun, the economically important clinical outcomein the treatment of clinical mastitis is not the absenceof bacteria, but rather the return of milk and udderto their normal state so that the cow’s milk can onceagain be sold.

All mastitis treatment studieshave to define an endpoint, usu-ally 10-28 days after diagnosis. In-fections occurring in the samecow or quarter after this endpointare assumed to be new infections.Absence of the original pathogenat the endpoint is assumed to bea cure. Few, if any, mastitis treat-ment studies focus on relapse orrecurrence rate. Perusal of on-farm treatment records shows thaton many farms many of the clin-ical cows are cows that have had bouts of clinicalmastitis before. In the future, treatment studiesshould focus on relapse rates and should use DNAfingerprinting technology to distinguish betweennew and chronic infections.

Antibiotic Therapy Of SpecificMastitis Pathogens

Only one common pathogen, Strep. ag., is highlysensitive to and easily cured by approved intramam-mary antibiotics used according to the label. In mostherds with low SCC the prevalence of Strep. ag. islow or zero. Many such herds have no Strep. ag. iso-lated from bulk tank samples or clinical cows foryears. In herds with Strep. ag. infected cows, use ofintramammary antibiotics is easily justified on med-ical, if not economic grounds, because it stops theshedding of bacteria by the cow with clinical mas-titis and because Strep. ag. is very sensitive to all ofthe antibiotic tubes on the market. Treatment of clin-ical mastitis in lactating cows is not effective, how-ever, in reducing prevalence in the herd unless it ispart of a total control program11. Only an integratedprogram of teat dipping, milking machine mainte-

nance, milking hygiene and dry cow treatment canbring about a long-term reduction in prevalence.

While all mastitis tubes carry a label claim forStaph., the cure rate is so low that dairymen are bestadvised to consider it negligible10,11,12. The cure ratein Staph. cows is low because the organism forms

microabscesses in the udder tis-sue outside the ducts, where intra-mammary drugs can not reach it.It also can survive inside whiteblood cells, makes L-forms, andcan acquire resistance to com-monly used antibiotics10. The besthope for successful antibiotictreatment of Staph- infected cowsis in young cows with recentinfections. Parenteral treatmentmay increase the chance of acure10, 28. In herds with a highprevalence of Staph. infections,

the emphasis should be on teat dipping, culling,milking machine maintenance, milking hygiene andsegregation of infected cows to gradually reduce theprevalence of the infection. Antibiotic treatment mayreduce shedding of Staph. by clinical mastitis cowsand thus help reduce the spread, but it will notreduce overall prevalence in the herd significantly11.

In herds with low SCC and low prevalence ofcontagious pathogens, clinical experience and pub-lished surveys1,2,4,7 show that about 15-40% of pre-treatment milk samples from cows with clinical mas-titis are negative for bacterial growth on blood agar.We presume that these samples containing too feworganisms for a positive culture result reflect the abil-ity of the cow’s immune system to rid the affectedquarter of pathogens. Antibiotic treatment of thesecows is difficult to justify; the problem is that we cannot know which cows they are until after treatmenthas to be initiated. The aim of treatment should beto return the quarter and the milk to normal, not toprevent the spread of infection. Anti-inflammatorydrugs or immune modulators would seem indicated,rather than antibiotics.



Only an integratedprogram of teatdipping, milking

machine maintenance,milking hygiene and drycow treatment can bring

about a long-termreduction in mastitis

prevalence.

A fairly large group of so-called “minor” patho-gens — minor in prevalence in the industry, not tothe infected cow or her owner — are refractory toall antibiotic treatment. This group includes the gen-era Mycoplasma, Pseudomonas, Pasteurella, Serra-tia, Prototheca, Mycobacterium, Nocardia, Bacillus,the yeasts and fungi, and Actinomyces pyogenes.

In surveys of clinical mastitis in herds with lowSCCs, coliform organisms account for about one-third of isolates from clinical cows. Coliform organ-isms can cause mastitis of severity ranging from sub-clinical to peracute. Erskine5,6 has shown that clini-cal signs appear in experimental coliform mastitisafter bacterial numbers in milk have peaked, andthat treatment of these cows with intramammarygentamicin did not affect clinical outcome. Toxicmastitis can be reproduced by infusing endotoxinwithout living organisms into the udder; most of theclinical signs of coliform mastitis are thought to bedue to the effects of endotoxin5. Treatment shouldtherefore aim primarily at removing endotoxin fromthe udder with frequent and complete milkout andat counteracting the effects of endotoxin with appro-priate anti-inflammatory and supportive treatments,such as fluids and calcium28. The most importantpart of a treatment protocol for coliform cows is tomilk the quarter out completely and often, possiblywith the help of OT injections. Unfortunately, treat-ment must begin before theorganisms involved can be iden-tified, and the appearance of theabnormal secretions alone is nota reliable basis for an etiologicdiagnosis, except perhaps in themost severe cases. No studieshave established the efficacy ofantibiotic treatment of chronic ormild clinical coliform mastitis.

The environmental strepto-cocci and the coliforms accountfor the majority of environmentalclinical mastitis cases where adiagnosis is obtained. Philpot11

cited a cure rate for clinical mas-

titis caused by environmental streptococci of 36%.Erskine6 states that acceptable cure rates (>75%) areattainable with a combination of intrammary antibi-otics and intramuscular procaine penicillin G. Tyler13

states that response of clinical Strep. uberis infectionsto antibiotic therapy during lactation is poor, althougha combination of parenteral and intramammary ery-thromycin appears to be the most efficacious treat-ment. Intramammary pirlimycin appears to be apromising treatment for clinical mastitis caused byenvironmental gram-positive organisms. More re-search is needed on these organisms, particularly onany long-range benefit from antibiotic treatment ineliminating chronic infections during lactation.

The challenges in treating clinical mastitis in a herdwith low SCC are the impossibility of establishing anetiologic diagnosis at the time of first treatment, thefact that about a third of cows being treated havealready cleared the infection, and the fact that in thecase of the coliforms at least, the primary aim of treat-ment has to be to counteract the effects of endotoxinrather than reducing bacterial numbers. This must beaccomplished without incurring undue risk of antibi-otic contamination of milk, in the absence of clearexperimental evidence from controlled trials thatantibiotic treatment of mastitis is efficacious or cost-effective. Clearly more research is needed.


Table 2: Pretreatment bacterial isolates of 3 treatment groups in ran -domized field trials of therapies for mild clinical mastitis, California,1991-92 (%)*.

Variable (Treatment) P valueOxytocin Amoxi-mast Cefa-lak

Coliform 33.3 41.9 37.3 0.93Streptococcus sp. 26.7 23.0 26.7Other 15.2 10.8 13.3Negative 24.8 24.3 22.7Number of cows 105 74 75

(*: Of the 94 coliforms, 81 (86%) were E.coli. Of the 65 Streptococcus sp., 27 (42%) wereS.uberis, 19 (29%) were S.dysgalactiae, and 14 (22%) were S.viridans. Of the 34 ‘other’ bac-teria, 14 (41%) were Staphylococcus sp. (primarily S.hyicus), 9 (26%) were mixed infections,3 (9%) were Bacillus sp. and 3 (9%) were Corynebacterium sp.)

California Study Of EfficacyOf Intrammary Antibiotics

A controlled study of intramammary treatmentfor mild clinical mastitis caused by environmentalbacteria was recently completed at the VeterinaryMedicine Teaching and Research Center of the Uni-versity of California, Davis24. We compared the effi-cacy of cephapirin and amoxicillin mastitis tubes tothat of OT alone in the treatment of mild clinicalenvironmental mastitis in 254 quarters. Both tubeswere used according to label instructions. Oxytocincows received 100 units of OT intramuscularly justbefore milking. No other treatments were used oncows in the study. No contagious pathogens wereisolated from any of the clinical cases. Cows treatedin the study had mild mastitis, that is, abnormal milkwith or without udder swelling, and no signs of sys-temic illness, and were randomly assigned to oneof the three treatments. Cows that did not improveor got worse during the observation period werecalled treatment failures and withdrawn from thetrial. A clinical cure was the return of the affectedquarter and milk to normal at the eighth milking afterinitial diagnosis and treatment. A bacteriologic curewas the failure to isolate the primary pathogen pre-sent at the first milking atthe eighth milking and at20 days after initial treat-ment. Results are shownin tables 2, 3 and 4.

There were no signifi-cant differences in over-all clinical cure rates bymilking 9 after diagnosisor in bacterial cure rateby day 21 betweenantibiotic- and OT-treated quarters, althoughthere was a significanteffect of antibiotics onclinical cure in the cate-gory of ‘other bacteria’,which were pathogensother than coliforms andstreptococci.

In this study tubes were used strictly according tolabel (two doses of cephapirin and three of amoxi-cillin) and OT was given at three consecutive milk-ings. The protocol may not correspond with the wayin which OT and antibiotic tubes are actually usedon most dairy farms.

Further analysis of the data from two of the threeherds involved in this trial by Van Eenennaam, etal.29 shows there was no economic advantage to theoxytocin treatments, despite the lower cost of treat-ment, because of the higher relapse rate and greaternumber of additional mastitis infections incurred bythe oxytocin group. There was no difference in thenumber of days of nonsalable milk over the lacta-tions of the cows in the study between the oxytocinand the antibiotic treatments. Many of the relapsesand reoccurrences in the oxytocin group occurredwhen the mastitic event was associated with an en-vironmental Streptococcus species. It may be thatin herds with a higher rate of CM infection causedby gram-negative organisms, the oxytocin-treatedcows would not have experienced more reoccur-rences and relapses. It should also be rememberedthat in this trial the antibiotics were used strictlyaccording to the label. On commercial dairies,



Table 3: Bacterial and clinical cure (%) by treatment group and herd in random -ized field trial of therapies for mild clinical mastitis, California, 1991-92.

Herd Treatment P valueOxytocin Amoxi-mast Cefa-lak

Bacterial cure %*Herd 1 (n=64) 10/26 (38.5) 9/20 (45.0) 11/18 (61.1) 0.33Herd 2 (n=31) 6/10 (60.0) 6/10 (60.0) 6/11 (54.5) 0.96Herd 3 (n=43) 12/21 (57.1) 3/11 (27.3) 5/11 (45.5) 0.27Total (n=138) 28/57 (49.1) 18/41 (43.9) 22/40 (55.0) 0.61

Clinical cure %Herd 1 (n=82) 23/33 (69.7) 20/24 (83.3) 17/25 (68.0) 0.41Herd 2 (n=86) 19/36 (52.8) 12/25 (48.0) 16/25 (64.0) 0.50Herd 3 (n=86) 28/36 (77.8) 18/25 (72.0) 17/25 (68.0) 0.69Total (n=254) 70/105 (66.7) 50/74 (67.6) 50/75 (66.7) 0.99

(*: Of 254 cases, 61 were culture negative prior to the 1st treatment, 43 were given additional treatmentprior to 9th milking, 2 were treated between 9th milking and 21 days, 2 were dried prior to 21 days, 4 wereculled before 9th milking, and 4 were culled before 21-day sample.)

where antibiotics may be used for more than two orthree milkings, the economic impact of oxytocinand antibiotics might be different.

It would appear, then, that the primary reason touse oxytocin as a treatment for CM rather thanantibiotics, at least in herds where environmentalStreptococci are the predominant cause of CM,would be to allow earlier culling of treated cowsand greater peace of mind to the dairyman regard-ing antibiotic residues in the bulk tank. While theshort term outcomes are the same among antibiotic-and oxytocin-treated cows, there may be long-termbenefits to using antibiotics in cows with gram-pos-itive environmental mastitis.

Van Eenennaam, et al. also found that overall lac-tation milk production was not affected by CM,when monthly test day data was compared. Thesedata may have masked short term milk losses thatwould have been obvious from daily milk yieldrecords. Also, higher-yielding cows are more likelyto develop CM, which may mask any milk yield losscaused by CM. However cows with CM were 2.1times more likely to be culled than their herdmates.

Efficacy And Safety Of OxytocinI have been unable to find controlled research

studies in the literature that document the effec-tiveness of OT therapy in clinical mastitis. Onestudy15 showed that OT levels were higher in cowsinoculated with 12.5 or 25 mcg of E. coli endotoxinin two quarters than in cows infused with saline.This suggests that lack of OT is not the reason forthe often observed failure of milk letdown in cowswith clinical coliform mastitis.

The optimal dosage of OT and the optimal timeof administration has not been established by re-search. Some clinicians have expressed the opinionthat a small dose should be given at the end of milk-ing to aid in the expulsion of residual milk and toreduce strippings. The label dose for aid in milk let-down is 10-20 IU, while that for obstetrical use is100 IU. One researcher recently confirmed that 20IU would elicit milk letdown in 1.5-2 minutes andwould also aid in ejection of strippings milk16.

Oxytocin is rapidly inactivated in the body andthe potential for toxicity is low. Occasional anaphy-lactic reactions are reported in women given OT at

parturition. No illeffects on health werefound in a study inwhich cows receivedtwice daily doses of20 IU OT at milkingthroughout lacta-tionl6. Reproductiveperformance was thesame in the treatedand control groups inthis study.

Oxytocin is part ofthe normal controlmechanism of luteol-ysis in the estrouscycle in cattle. Oxy-tocin is secreted bythe corpus luteumand acts on uterinereceptors in the estro-gen-primed uterus


Table 4: Bacterial and clinical cure (%) by treatment group and bacterium isolatedat pretreatment sampling in randomized field trial of therapies for mild clinical mas -titis, California, 1991-92.

Herd Treatment P valueOxytocin Amoxi-mast Cefa-lak

Bacterial cure %*Coliforms (n=63) 10/26 (38.5) 9/20 (45.0) 11/18 (61.1) 0.33Streptococcus sp. (n=49) 6/10 (60.0) 6/10 (60.0) 6/11 (54.5) 0.96Other bacteria (n=26) 12/21 (57.1) 3/11 (27.3) 5/11 (45.5) 0.27Positive cultures (n=138) 28/57 (49.1) 18/41 (43.9) 22/40 (55.0) 0.61

Clinical cure %Coliforms (n=94) 23/33 (69.7) 20/24 (83.3) 17/25 (68.0) 0.41Streptococcus sp. (n=65) 19/36 (52.8) 12/25 (48.0) 16/25 (64.0) 0.50Other bacteria (n=34) 28/36 (77.8) 18/25 (72.0) 17/25 (68.0) 0.69No bacteria isolated (n=61) 24/26 (92.3) 13/18 (72.2) 13/17 (76.5) 0.18Total cultures (n=254) 70/105 (66.7) 50/74 (67.6) 50/75 (66.7) 0.99

(*: Of 254 cases, 61 were culture negative prior to the 1st treatment, 43 were given additional treatment priorto 9th milking, 2 were treated between 9th milking and 21 days, 2 were dried prior to 21 days, 4 were culledbefore 9th milking, and 4 were culled before 21-day sample. There were no contagious pathogens cultured.)

during late diestrusl7. The binding of OT to the uter-ine receptors in turn triggers the pulsatile secretionof prostaglandin F2‡ (PGF) by the uterus. This pos-itive feedback mechanism causes luteolysis andallows estrus to occur. Injection of 230 IU of OT incows on days 2-6 of the estrous cycle caused a sig-nificant increase in PGF concentration in the bloodand shortened the cycle of two of six treated cowsto 10-12 days18. However in another study injectionof about 230 IU (.33 IU/kg) at days 5, 10 and 15 ofthe cycle had no effect on cycle length, estradiol, orprogesterone concentrations19. On the other hand,continuous infusion of OT in open heifers causedlengthened estrus cycles17. The PGF response to OTinjection is suppressed after day 6 of the cycle andrestored at day 13-1620. Immunization of sheepagainst OT prolongs the luteal phase of the estrouscycle21. OT also has a direct inhibitory effect ongonadotrophin-stimulated steroid hormone (prog-esterone, in particular) in isolated luteal cells21. Exo-genous OT does not induce parturition in late-ges-tation cattle.

Oxytocin also has a role in the effects of heatstress on reproduction. Chronically heat-stressedewes have smaller lambs than unstressed ewes,partly in response to reduced uterine blood flow22.The decrease in uterine blood flow is accompaniedby a 60% increase in serum OT. Uterine blood flowwas also reduced by exogenous OT and antidiuretichormone (ADH) injections. OT and ADH are simi-lar in structure and are both secreted by the poste-rior pituitary. Heat-stressed pregnant heifers tendedto have a higher PGF response to the injection of100 IU OT. Five of six heat stressed pregnant heifers,compared to 1/5 nonstressed heifers, were classi-fied as responders to OT (PGF concentration >193pg/ml)23. It would appear from this study that heatstress antagonizes the suppressive effect of the em-bryo on uterine secretion of PGF in response to OT.

In summary, OT used at the low doses used formilk ejection has little toxic potential aside from rareanaphylactic reactions. However, at higher doses ithas been reported to affect cyclicity of cows in theearly and late parts of the cycle and the level of prog-

esterone secreted by the corpus luteum. Heat-stressed animals may be slightly more likely to abortdue to OT-induced PGF release from the uterus, andchronic OT administration may reduce uterineblood flow and fetal size and viability. One studyreported no health or reproductive effects fromtwice-daily injections of 20 IU of OT16. Since endo-toxin can cause prostaglandin release and luteoly-sis, it would be hard to determine whether alteredcyclicity or abortion was due to mastitis itself or toOT used as an aid in mastitis therapy.

Protocols For MastitisTreatment On Dairy Farms

In the past, the standard recommendation was totreat all cows with clinical mastitis with antibiotictubes used according to the label. In herds with lowSCC where all clinical mastitis is caused by environ-mental bacteria, we can design better treatment pro-tocols that minimize antibiotic use, reduce the riskof residues, and still allow flexibility to beef affectedcows if treatment does not work. A responsible treat-ment protocol requires that permanent records ofclinical mastitis be kept so that a cow’s past historycan be consulted before treatment is initiated. Sincealmost any rational treatment protocol for clinicalmastitis will include off-label treatments, the co- op-eration of a veterinarian is essential for its design andimplementation.

Clinical mastitis should be classified before treat-ment as mild or severe. Mild mastitis would be char-acterized by abnormal milk and slight udder swell-ing, while severe mastitis would include abnormalmilk, severe swelling, the risk of losing the quarter,and systemic illness (fever, off feed, diarrhea).

Before a protocol is put in place, the veterinarianshould collect and analyze the results of sampling ofclinical mastitis cows to determine the pathogensgenerally involved on the particular farm in differentseasons. On a farm where clinical mastitis is causedby Strep. ag., for example, antibiotic tubes shouldused on all clinical cases. On a farm where a thirdof the clinical samples show no growth and half yieldE. coli, antibiotic use may be justified for very fewcows. In a herd with a high incidence of envi-



ronmental gram-positive infec-tions, some combination of intra-mammary and systemic antibi-otics may be effective. Dairy per-sonnel should be trained to lookat the cow’s record before begin-ning a course of lactating cowtreatment. The people making thetreatment decisions, usually milk-ers or herdsmen, need to betrained and trusted to make thesedecisions properly. The veterinar-ian and the owner should developa treatment protocol based on the known past his-tory of pathogens in the herd, age of the cow, repro-ductive status, milk yield, relative value in the herd,past mastitis history, other unsoundnesses (locomo-tor problems, poor udder conformation, etc.), and theseverity of clinical signs. For example, a cow that isbelow the herd average, open, and late in lactationwill most likely be culled eventually anyway andmight as well be culled now that she has mastitis. Anaverage first-lactation cow that is late in gestationshould be dried off early, since dry cow preparationsare stronger, stay in the udder longer, are more likelyto clear up the infection than lactating cow tubes,and present less risk of contaminating the bulk tankwith antibiotics. Cows with persistent or recurringinfections despite past treatment are unlikely torespond to a repetition of the same treatment proto-col. The risky approach on these cows is to turn toextralabel use of parenteral antibiotics, with all of therisk of illegal residues it entails. A safer approach isto evaluate the cow’s record and the severity of theinfection and decide either to cull the cow, dry heroff, treat her, or to let her recover on her own. Ayoung, high-yielding cow in early lactation with mildmastitis might be treated aggressively, with an empha-sis on frequent and complete milkout.

Treatment protocols should be modified to fit theculling philosophy and goals of each producer. Aproducer who is trying to build up herd numbers,for example, may be more inclined to dry off a preg-nant cow with clinical mastitis than one whose facil-

ity is overcrowded and is lookingfor room for a new heifer.

On large dairies an aid in themanagement of clinical mastitisis to have a designated mastitisstring, which is milked last, justbefore the hospital or antibioticstring. The mastitis string ismilked into the bulk tank. It con-tains all cows that have had clin-ical mastitis during the currentlactation, chronic high SCCcows, and cows known to be

infected with Staph. that the owner does not wantto cull. On some dairies it might include slow-milk-ing cows and cows with poor udder shape thatrequire extra attention at milking time. On othersthe slow cows are in a separate group. Cows in themastitis string are generally not to be treated withantibiotics when they get clinical mastitis again.They are either culled or milked out with the aid ofOT injections until their milk is normal. Since abnor-mal milk may not be put into the bulk tank, cows inthis group with clinical mastitis must either bemilked into a separate bucket or put in the hospitalstring until their milk is normal. Cows may leave themastitis pen only to be dried-off or culled, or if theirindividual SCC remains below 200,000 for threeconsecutive test days and they are not known to beinfected with a contagious pathogen.

On dairy farms where facilities permit, one smallpen may be designated a non-antibiotic hospital.This pen can then be milked at twice the frequencyof the other pens by bringing the cows to be milkedin the middle of each shift. Since no antibiotics areused in this pen, the pipeline does not have to bewashed after it is milked, and the milk can be di-verted to calf milk or put down the drain.

Here is a suggested treatment protocol for dairyfarms with no clinical mastitis caused by contagiousorganisms. It is assumed that the cow in question isconsidered to be worth treating. Cows that have hadmore than three or four bouts of clinical mastitis ina lactation should be considered for the chronic pen,


Since almost anyrational treatment

protocol for clinical mas -titis will include off-labeltreatments, the co- op -eration of a veterinarian

isessential for its designand implementation.

culling or drying off. Very mild cases, where a fewflakes of garget in the first squirts of milk give wayto normal milk, would be recorded but milked intothe bulk tank. In mild cases where milk remainedabnormal but the cow was not off feed or depressed,the cow would be milked more frequently than nor-mal with the aid of OT injections. A sample wouldbe taken at initial diagnosis, frozen, and discardedif the cow responded to the frequent milkout treat-ment. If the quarter did not improve rapidly, the sam-ple would be taken to the laboratory. If the bacteriaisolated are susceptible to treatment, antibiotic treat-ment would be initiated. If not, the cow would con-tinue on frequent milkout, or the quarter would bedried off, or the cow sold. In cases of severe, acutemastitis in which the cow become depressed andgoes off feed, treatment would emphasize frequentmilkout, use of anti-inflammatory drugs, and sup-portive care. With this treatment protocol antibioticuse is limited to the comparatively small group ofmastitis cows that will benefit from it, and residuerisk is greatly reduced.

Treatment of clinical mastitis is the most commonuse of antibiotics on dairy farms and the most com-mon cause of illegal antibiotic residues. On well-managed dairy farms most mastitis is caused by theenvironmental pathogens. There is no data fromwell-controlled studies demonstrating the efficacyof antibiotic treatment of clinical mastitis caused bythe environmental pathogens, nor on any benefit ofantibiotic treatment on chronic or persistent infec-tions. However, even in the absence of data the vet-erinarian can be very helpful in developing treat-ment protocols that greatly reduce the use of antibi-otics and decrease the risk of violative residues.

References:1. Anderson, K.L., A.R. Smith, B.K. Gustafsson,

S.L. Spahr, and H.L. Whitmore, 1982. Diagnosis andtreatment of acute mastitis in a large dairy herd. J.Am. Vet. Med. Assn. 181:690.

2. Bennett, R.H., 1990. Clinical mastitis fromenvironmental pathogens: analysis of a large com-mercial dairy. Proc. Int. Symp. Bov. Mastitis,National Mastitis Council, 181.

3. Chamings, R.J., 1984. The effect of not treat-ing mild cases of clinical mastitis in a dairy herd.Vet. Rec. 115:499.

4. Erskine, R.J., R.J. Eberhart, L.J. Hutchinson, S.B.Spencer, and M.A. Campbell, 1988. Incidence andtypes of clinical mastitis in dairy herds with high andlow somatic cell counts. J. Am. Vet. Med Assn.192:761.

5. Erskine, R.J., R.C. Wilson, and M.G. Riddell,Jr., 1990. The pharmacokinetics and efficacy ofintramammary genatamicin for the treatment of col-iform mastitis. Proc. Int. Symp. Bov. Mastitis,National Mastitis Council, 256.

6. Erskine, R.J., 1991. Therapy of clinical masti-tis: successes and failures. Proc. Nat. Mastitis Coun-cil, 30:40.

7. Gonzalez, R.N., D.E. Jasper, N.C. Kronlund,T.B. Farver, J.S. Cullor, R.B. Bushnell, and J.D.Dellinger, 1990. Clinical mastitis in two californiadairy herds participating in contagious mastitis con-trol programs. J. Dairy Sci. 73:648.

8. Hogan, J.S., K.L. Smith, K.H. Hoblet, P.S.Schoenberger, D.A. Todhunter, W. D. Hueston, D.E.Pritchard, G.L. Bowman, L.E. Heider, B.L. Brockett,and H.R. Contrad, 1989. Field survey of clinicalmastitis in low somatic cell count herds. J. Dairy Sci.72:1547.

9. Morse, D., M.A. DeLorenzo, R.P. Natzke, andD.R. Bray, 1988. Characterization of clinical mas-titis records from one herd in a subtropical envi-ronment. J. Dairy Sci. 71:1396.

10. Owens, W.E., S.C. Nickerson, J.L. Watts, andR.L. Boddie, 1990. Antibiotic concentrations inmammary tissue and milk following intramammaryand/or intramuscular therapy.” Proc. Int. Symp. Bov.Mastitis, National Mastitis Council, pp. 276.

11. Philpot, W.N. 1979. Control of mastitis byhygiene and therapy. J. Dairy Sci. 62:168.

12. Soback, S., 1990. Mastitis therapy — past,present, and future. Proc. Int. Symp. Bov. Mastitis,National Mastitis Council, pp. 244.

13. Tyler, J.W., R.C. Wilson, and P. Dowling,1992. Treatment of subclinical mastitis. Vet. Clin. N.Am. (Food Animal Practice) 8 (1):17.



14. Ziv, G., 1992. Treatment of peracute andacute mastitis. Vet. Clin. N. Am. (Food Animal Prac-tice) 8 (1):1.

15. Gorewit, R.C., 1993. Effects of intramammaryendotoxin infusion on milking- induced oxytocinrelease. J. Dairy Sci. 76:722.

16. Nostrand, S.D., D.M. Galton, H.N. Erb, andD.E. Bauman, 1991. Effects of daily exogenous oxy-tocin on lactation milk yield and composition. J.Dairy Sci. 74:2119.

17. Howard, H.J., D.E. Morbeck, and J.H. Britt,1990. Extension of oestrous cycles and prolongedsecretion of progesterone in non-pregnant cattleinfused continuously with oxytocin. J. Repro. Fert.90:493.

18. Oyedipe, E.O., B. Gustafsson, and H. Kin-dahl, 1984. Blood levels of progesterone and 15-keto-1,14 dihydro prostaglandin F2‡ during theestrous cycle of oxytocin-treated cows. Theri-ogenology 22:329.

19. Vighie, G.H., R.M. Liprap, and W.G. Ether-ington, 1991. Oxytocin-prostaglandin interrela-tionships in the cow with pyometra. Therogenology35:1121.

20. Silvia, W.J. and M.C. Taylor, 1989. Relation-ship between uterine secretion of prostaglandin F2‡induced by oxytocin and endogenous concentra-tion of estradiol and progesterone at three stages ofthe bovine estrous cycle. J. Anim. Sci. 67:2347.

21. Flint, A.P.F. and E.L. Sheldrick, 1983. Evi-dence of a systemic role for ovarian oxytocin inluteal regression in sheep. J. Repro. Fert. 67:215.

22. Dreiling, C.E., F.S. Carman, and D.E. Brown,1991. Maternal endocrine and fetal metabolicresponse to heat stress. J. Dairy Sci. 74:312.

23. Wolfenson, D., F.F. Bartol, L. Madinga, C.M.Barros, D N. Marple, K. Cummins, D.W. Wolfe,M.C. Lucy, T.E. Spencer, and W.W. Thatcher, 1993.Secretion of prostaglandin F2‡ and oxytocin duringhyperthermia in cyclic and pregnant heifers. Theri-ogenology 39:1129.

24. Guterbock, W.M., A.L. Van Eenennaam, R.J.Anderson, I.A. Gardner, J. S. Cullor, and C.A. Hol-berg, 1993. Efficacy of intramammary antibiotics fortreatment of mild clinical mastitis caused by envi-ronmental pathogens. J. Dairy Sci. 76:3437.

25. Hogan, J.S., K.L. Smith, D.A. Todhunter, andP.S. Schoenberger, 1987. Efficacy of antibiotic infu-sion products for lactational therapy of mastitiscaused by environmental pathogens. p. 1 in Proc.Int. Mastitis Symposium, Macdonald College, Ste.Anne, PQ, Canada.

26. Miller, C.C., 1993. Unpublished data. TheUpjohn Company.

27. Yancey, Jr., R.J., R.A. Rzepkowski, S.T.Chester, and C.W. Ford, 1989. Efficacy of pirlimycinhydrochloride in the treatment of experimentally-induced staphylococcal mastitis in lactating dairycows. J. Dairy Sci. 72 (Supp. 1):22.

28. Erskine, R.J., J.H. Kirk, J.W. Tyler, and F.J.DeGraves, 1993. Advances in the Therapy for Mas-titis. Vet. Clin. N. Am. 9 (3):499.

29. Van Eenennaam, A.L., Gardner, I.A., Holmes,J., Perani, L., Anderson, R.J., Cullor, J.S., and Guter-bock, W.M. Financial Analysis of Alternative Treat-ments for Clinical Mastitis Associated with Envi-ronmental Pathogens. J. Dairy Sci., accepted forpublication, 1995.



notes

Neosporosis: ANewly RecognizedCause Of Abortion

In Dairy CattleBy Patricia A. Conrad, DVM, PhD

Mark L. Anderson, DVM, PhDBradd C. Barr, DVM, PhDDepartment of Pathology,

Microbiology & Immunology,and the California Veterinary Diagnostic Laboratory

School of Veterinary MedicineUniversity of California,Davis, CA 95616-8739

916-752-1385fax 916-752-3349


NN eospora is a newly recognized genus thatwas first identified as a Toxoplasma-likeprotozoa in dogs with encephalomyelitis

and myositis15 and later shown to be the sameNeospora caninum parasite that was isolated froma litter of puppies in the United States14,24,27,29.

The genus designation Neospora has since beenapplied to a similar protozoal parasite identified inlivestock9,51. In 1991, the first bovine Neospora iso-lates were obtained from aborted fetuses and theseisolates have been maintained in continuous cellculture18. Whether the canine isolate (Neospora can-inum) and bovine isolate represent identical or dif-ferent species is not known. At present, the infec-tion in livestock is most appropriately referred to asa Neospora species.

Neospora have morphologic similarities to Tox-oplasma gondii, but can be antigenically differenti-ated by immunohistochemistry.12 By light micro-scopy, Neospora can only be differentiated fromToxoplasma in the tissue cyst stage where Neosporaoften has a thicker cyst wall. In addition, there aredistinct ultrastructural differences between Toxo-plasma gondii and Neospora.12,39

Infection due to Neospora has been reported invarious species of livestock, including cat-tle1,5,8,9,11,12,20,25,28,30,33,35,38,41,43,46,49,50,51,52,56 sheep26,31 goats11,23

horses34 and deer55. Although only recently recog-nized, bovine neosporosis has emerged as an impor-tant reproductive disease. Since its first associationwith an abortion storm in 1987 in a dairy in NewMexico51 there have been reports of Neospora abor-tions in California and the Midwest which have con-firmed this infection as a significant cause of abor-tion, particularly among dairy cattle1,5,9,41,49. Retro-spective studies in California suggest that the para-site has been endemic since at least 19856.

In California, 18-19% of all aborted bovinefetuses submitted to the California Veterinary Diag-nostic Laboratory System (CVDLS) are diagnosedwith this infection5,9. In dairy cattle submissions fromCalifornia, the proportion of Neospora abortion iseven higher, 24.4%6. In a Midwest survey, Neosporainfection was identified in 2.7% of all cattle abor-

tions and was the largest cause of abortion in dairycattle submissions.41

Bovine neosporosis has a worldwide distributionand has been diagnosed in the United States,38

Canada,*,38 Mexico,1 Britain,20,44,46 Netherlands,56

Denmark,2 Australia,25,42 New Zealand,52 SouthAfrica,35 and Japan*,43. Within the United States 28states have reported cases including Alabama,38 Ari-zona,*,41 California,3-6,8-12 Colorado,*,49 Georgia,38

Idaho,* Illinois,* Indiana,28 Iowa,41 Kansas,* Mary-land,*,33 Michigan,* Minnesota,*,41 Missouri,* Mon-tana,* Nebraska,38 New Mexico,51 New York,* NorthDakota,* Ohio,* Oklahoma,* Texas,*,41 SouthDakota,41 Utah,* Virginia,* Washington,48,50 West Vir-ginia* and Wisconsin*,41.

Pathogenesis:The pathogenic potential of bovine Neospora sp.

has been confirmed by experimental infection ofpregnant cattle resulting in fetal death and in thebirth of an in utero exposed or congenitally infectedcalf13. Neospora caninum from dogs also has beenexperimentally inoculated into pregnant cattle andsheep, resulting in transplacental fetal infection in acow and abortion in sheep31,32.

The natural route of infection and life cycle ofNeospora is unknown, but similarities to other api-complexan coccidia, particularly Toxoplasma, sug-gests that postnatal infection probably is acquiredthrough oral ingestion of coccidial oocysts shedfrom an unidentified carnivorous definitive host.Attempts are being made to identify the definitivehost of bovine Neospora. To date, dogs, cats, ratsand mice have been screened for Neospora coc-cidia following experimental infection with bovineNeospora sp. (Conrad P and Barr B, unpublisheddata, 1992) and dogs, cats, and raccoons have beenscreened for N. caninum coccidia following exper-imental infections with N. caninum38, but no fecaloocysts identified as Neospora have been identifiedin these species. Tachyzoites and tissue cysts are thetwo morphologic forms currently identified.

Clinical Presentation:Although congenital Neospora infections have

been diagnosed in most of the domestic livestock


Neosporosis

species, cattle are the onlylivestock species in whichthere is sufficient informationavailable concerning the nat-ural infection to describe itsclinical features. There are nosigns of clinical illness in cowsthat abort due to Neosporainfection. The aborted fetusesare usually autolyzed, with nogross lesions, and placentasare not retained. Abortionshave been diagnosed in both heifers and cows from3 months gestation to term5,9,33. Whether Neosporainfection can cause reproductive problems in thefirst trimester of gestation is unknown. A majority(78%) of Neospora abortions occur between 4-6months gestation and this pattern of mid-gestationabortion is distinctive from other diagnosed causesof infectious abortion in dairy cattle which tend tooccur later in gestation6.

While Neospora infections occur in both dairyand beef cattle, most reports attributing significantnumbers of abortions to this infection have beenassociated with dairy cattle, particularly those in dry-lot dairies1,3-6,8,9,41,49,51. This apparent disparity betweenbeef and dairy cattle is not thought to representbreed susceptibility, since beef cattle have beenshown to be susceptible to experimental infection13

and both congenital infections and abortions due toNeospora have been documented in beefbreeds*,28,30,33,48.

It is probable that the environment of the drylotdairy is more conducive to the spread and trans-mission of this disease. Cattle in drylot dairies aredensely populated and fed a variety of harvestedfeeds and commodities which are frequently storedon or around the dairy prior to being mixed and fed.These feeding practices offer many opportunities forfecal contamination, either on the dairy or in thecrop in the field, of any of these individual rationcomponents which would then be mixed and fed,efficiently exposing much of the herd. This patternof increased exposure and disease associated with

intensive management mim-ics factors affecting the inci-dence of Toxoplasma abor-tion in sheep flocks.

Neospora infection hasbeen identified throughoutCalifornia in over a third ofthe dairy herds submittingaborted fetuses to theCVDLS6,9. The herd incidenceof abortion due to this infec-tion can be quite variable.

Rare sporadic cases may occur in some dairies witha nominal abortion rate. However, explosive out-breaks of Neospora abortion may occur.

A well documented example involved a group of147 drylot dairy heifers in which 27 (18%) abortedduring a six-week period and all fetuses examined(17) were diagnosed with Neospora infection(Reynolds J, personal communication, Nov. 1993).In some instances, up to 5% of pregnant cattle haveaborted due to neosporosis within one to threemonths. Annual herd abortion rates up to 30% havebeen reported in dairies with Neospora abortionsand these abortions may continue to occur over aperiod of several years*,1,49. Over a one-year periodof time, all aborted fetuses available on 26 selectedCalifornia dairies were collected and submitted tothe CVDLS for diagnosis. A total of 266 abortionswere submitted, of which 113 (42.5%) were con-firmed Neospora abortions from 19 dairies (73%)7.In addition to abortion, fetal mummification hasbeen associated with Neospora outbreaks*,49.Neospora abortions occur throughout the year butthere is possibly a small increased risk of abortionduring the late fall and winter53.

Bovine fetal Neospora infection does not alwaysproduce fetal death resulting in abortion or stillbirth.Fetal infection may result in the birth of live full-termcongenitally affected calves11,12,20,25,28,30,33,44,48. Centralnervous system infection and damage in thesecalves results in highly variable clinical signs whichare often limited to limb dysfunctions, ranging frommild proprioceptive defects to complete paralysis.


While Neospora infectionsoccur in both dairy and beef

cattle, most reports attributingsignificant numbers of abor -tions to this infection havebeen associated with dairycattle, particularly those in

drylot dairies

Microscopically, there is a multifocal protozoal en-cephalomyelitis which may be particularly local-ized in the spinal cord gray matter. However, calvesmay have serologic and histopathologic evidenceof in utero Neospora exposure or congenital infec-tion with no obvious signs of clinical postnatal dis-ease. A consistent finding in these calves is a highprecolostral antibody titer toNeospora which are useful indetecting in utero exposed or con-genitally infected calves11. In a sur-vey of calves on a dairy with a pre-vious history of Neospora abor-tions, 67/189 newborn calves(35%) had serologic evidence ofin utero Neospora infection, withno evidence of increased morbid-ity or mortality in these calves47.The apparent wide variability inclinical presentation of these inutero exposed or congenitally infected calves maybe due to multiple factors, including the age andimmune development of the fetus at the time ofexposure to Neospora, as well as the distribution ofthe lesions in the central nervous system.

Evidence is accumulating that cows that abort aNeospora-infected fetus may have additional in-fected fetuses in subsequent pregnancies. Barr andcolleagues identified 5 calves born to 4 cows withNeospora abortions in the previous pregnancy. Inall calves there was serologic and histopathologicevidence of congenital infection11.

Repeat abortions can also occur. In a survey ofabortions in drylot dairies in California, two con-firmed Neospora abortions were identified in 4 of41 cows in which information concerning otherpregnancies was available7. It is not known whetherthese repeat transplacental infections are the resultof a release of parasites from tissue cysts in the damor from reinfection of the dam from the environ-ment. However, there is recent evidence that sug-gests that chronic persistent infections do occur. Ina survey of heifer calves in a known Neospora dairyherd, 25 calves with serologic evidence of congen-

ital exposure were compared with 25 serologicallynegative cohorts. The two groups were similar untilpregnancy and calving. At the present time 20 of the50 heifers have calved. All calves born to heiferswith an history of congenital Neospora exposurehave had elevated Neospora titers (8 of 8) and allnegative heifers have had serologically negative

calves (12 of 12) (Mark Ander-son and Jim Reynolds, unpub-lished data, 1995).

The results suggest both thata chronic latent infection canoccur with Neospora and, mostinterestingly, that there is verti-cal transmission of this diseasethrough generations of cattlewith little obvious clinicalsymptoms.

Diagnosis:The confirmation of a suspect

Neospora infection will require the assistance of aveterinary diagnostic laboratory. The preferred sam-ples in cases of abortion include one or moreaborted fetuses submitted with placenta and serafrom the dam. The aborted fetus is usually autolyzedwith serosanguinous fluid accumulation in bodycavities. Rarely there are subtle gross lesions, con-sisting of pale white foci in the skeletal muscles orthe heart. Histologic lesions consist of widespreadnonsuppurative infiltrates. The most diagnosticallysignificant lesions are found in the brain and con-sist of scattered foci of nonsuppurative cellular infil-trates with occasional foci of necrosis. Protozoa arenot usually seen on routinely stained slides. Otherhistologic lesions that are consistently found includenonsuppurative epicarditis and/or myocarditis, focalnonsuppurative myositis and nonsuppurative por-tal hepatitis, frequently with focal hepatic necrosis.9The presumptive diagnosis of protozoal infectioncan usually be made on the basis of histologiclesions. Immunohistochemistry using antibodies toNeospora caninum37 or the bovine Neospora iso-late12,13 is an effective method to identify Neosporain fetal tissues and establish a definitive diagnosis.


Neosporosis

Evidence is accumu -lating that cows thatabort a Neospora-infected fetus mayhave additional in -

fected fetuses in sub -sequent pregnancies.

Recently, a monoclonal antibody against Neo-spora caninum has been developed which can alsobe used to detect infection in aborted fetuses17.Neospora immunohistochemistry is most success-ful on sections of fetal brain, although the parasitesare also frequently present in the lung, kidney andskeletal muscle (Anderson M., unpublished data,1994). Immunohistochemistry has been successfullyemployed to diagnose Neospora infections in mum-mified fetuses although the autolytic state of thesefetuses diminishes the diagnostic accuracy (Ander-son M, Barr B, unpublished data, 1994).

Diagnosis of congenital Neospora infection incalves on the basis of necropsy and histopathologymay be difficult due to the variability of histologiclesions and numbers of parasites present12. The mostcharacteristic lesions are in the spinal cord, con-sisting of a multifocal nonsuppurative myelitis. Insome cases thick-walled tissue cysts may be presentwithin neurons. However, these tissue cysts may beextremely rare in many in utero exposed calves,making it difficult to establish a diagnosis on thebasis of Neospora immunohistochemistry alone.

Neospora serology, utilizing an indirect fluores-cent antibody (IFA) test, has proven effective indetecting elevated Neospora antibodies in the serumof congenitally infected or in utero exposedcalves12,19. In addition, the Neospora IFA test mayalso be useful in establishing the diagnosis inaborted fetuses, since most infected fetuses olderthan 5 months gestation have elevated Neosporaantibody titers. However, just as with Toxoplasmainfections, a negative fetal Neospora IFA titer doesnot rule out the possibility of infection.

While serology is an effective diagnostic tool inidentifying Neospora infection in aborted fetusesand in utero exposed calves, the use of NeosporaIFA for serodiagnosis in the adult cow may be lessreliable. A significant portion (22%) of cows abort-ing a Neospora infected fetus had Neospora IFAtiters that were within 2 dilutions of titers in pre-sumed noninfected cattle19. In addition, within 2-5months following abortion, the previously elevatedtiters in cows aborting a Neospora infected fetus

may drop to levels similar to noninfected cattle19.Laboratories utilizing this test must establish appro-priate cut- off titers using standardized sera andshould attempt to confirm their positive results bythe identification of parasites in aborted fetuses.

Control And Prevention:At present, there are no proven methods available

for the control, prevention or treatment of bovineneosporosis as there is insufficient information onthe biology of this parasite, including the mode oftransmission, on which to base specific recommen-dations. However, it is prudent to remove all poten-tially infected tissues, such as aborted fetuses andplacentas from the environment, that might serve asa source of infection for susceptible hosts. In addi-tion, fecal contamination of feed and water sourcesby other animals should be minimized. It is appar-ent that fecal contamination of the environment orfeeds of cattle is extremely common since virtuallyall cattle are infected with Sarcocystis cruzi throughingestion of coccidia from a canidae definitive host.As is the case with toxoplasmosis, development ofan effective Neospora vaccine will be extremely dif-ficult. At present, no culling recommendations canbe offered for cows that have a Neospora abortion.Although repeat abortions or repeat congenital infec-tions might occur in these animals, there is insuffi-cient information available to estimate their futurereproductive performance.

References:*: Anderson, ML, Barr BC, Conrad PA: Unpub-

lished Neospora immunohistochemistry results fromsubmissions to California Veterinary Diagnostic Lab-oratory, 1995.

1. Abbitt B, Craig TM, Jones LP, et al. Protozoalabortion in a herd of cattle concurrently infectedwith Hammondia pardalis. J Am Vet Med Assoc203:444, 1993.

2. Agerholm JS, Barr BC. Bovine abortions asso-ciated with Neospora in Denmark. Dansk Veteri-naer Tidsskrift [Danish Veterinary J], in press, 1995.


3. Anderson ML, Barr BC, Conrad PA, et al:Bovine Protozoal Abortions in California. TheBovine Practitioner 26:102, 1991.

4. Anderson, ML, Blanchard, PC, Barr BC, et al:A survey of causes of Abortion in San Joaquin Val-ley, California. J Vet Diagn Invest 2:283, 1990.

5. Anderson ML, Blanchard PC, Barr BC, et al:Neospora-like protozoan infection as a major causeof abortion in California dairy cattle. J Am Vet MedAssoc 198:241, 1991.

6. Anderson ML, Picanso J, Thurmond M et al.Epidemiological investigations of bovine protozoalabortion in California dairy herds. Proc XVII WorldBuiatrics Cong and XXV Am Assoc Bovine PractConf 2:74, 1992.

7. Anderson, ML, Palmer C, Thurmond M, et al.Prospective survey of Neospora abortions inselected California dairies. J Am Vet Med Assoc,accepted for publication, 1994.

8. Barr BC, Anderson ML, Blanchard PC, et al:Bovine fetal encephalitis and myocarditis associatedwith protozoal infection. Vet Pathol 27:354, 1990.

9. Barr BC, Anderson ML, Dubey JP, et al:Neospora-like protozoal infections associated withbovine abortions. Vet Pathol 28:116, 1991.

10. Barr BC, Anderson ML, Woods LW, et al.Neospora-like protozoal infections associated withabortions in goats. J Vet Diagn Invest 4:365, 1992.

11. Barr BC, Conrad PA, Brietmeyer R, et al: Con-genital Neospora infection in calves born from cowsthat had previously aborted Neospora-infectedfetuses: Four cases (1990-1992). J Am Vet MedAssoc 202:113, 1993.

12. Barr BC, Conrad PA, Dubey JP, et al:Neospora-like encephalomyelitis in a calf: pathol-ogy, ultrastructure, and immunoreactivity. J Vet DiagInvest 3:39, 1991.

13. Barr BC, Rowe JD, Sverlow KW, BonDurantBH, Ardans AA, Oliver MN, Conrad PA. Experi-mental reproduction of bovine fetal Neospora infec-tion and death with a bovine Neospora isolate. J VetDiagn Invest, in press, 1994.

14. Bjerkas I & Dubey JP: Evidence that Neosporacaninum is identical to the Toxoplasma-like para-site of Norwegian dogs. Acta Vet Scand 32:407,1991.

15. Bjerkas I, Mohn SF, Presthus J. Unidentifiedcystforming sporozoan causing encephalomyelitisand myositis in dogs. Z. Parasitenkd 70:271, 1984.

16. Buxton D, Finlayson J: Experimental infectionof pregnant sheep with Toxoplasma gondii: patho-logical and immunological observations on the pla-centa and foetus. J Comp Path 96:319, 1986.

17. Cole RA, Lindsay DS, Dubey JP, et al. Detec-tion of Neospora caninum in tissue section using amurine monoclonal antibody. J Vet Diagn Invest5:579, 1993.

18. Conrad PA, Barr BC, Sverlow KW, et al: Invitro isolation and characterization of a Neosporasp. from aborted bovine fetuses. Parasitology106:239, 1993.

19. Conrad PA, Sverlow KW, Anderson ML, et al.Detection of serum antibody responses in cattle withnatural or experimental Neospora infections. J VetDiagn Invest 5:572, 1993.

20. Dubey JP. Congenital neosporosis in a calf.Vet Rec 125:486, 1989.

21. Dubey JP: A review of Neospora caninumand Neospora-like Infection in animals. J ProtozoolRes 2:40, 1992.

22. Dubey JP: Toxoplasma, Neospora, Sarcocys-tis, and other tissue cyst-forming coccidia of humansand animals. In Kreier JP:Parasitic Protozoa, ed 2.New York, Academic Press Inc, 1993.

23. Dubey JP, Acland HM, Hamir AN. Neosporacaninum (Apicomplexa) in a stillborn goat. J Para-sitol 78:532, 1992.

24. Dubey JP, Carpenter JL, Speer CA, et al:Newly recognized fatal protozoan disease of dogs.J Am Vet Med Assoc 192:1269, 1988.

25. Dubey JP, Hartley WJ, Lindsay DS. Congen-ital Neospora caninum infection in a calf with spinalcord anomaly. J Am Vet Med Assoc 197:1043, 1990.

26. Dubey JP, Hartley WJ, Lindsay DS, et al: Fatalcongenital Neospora caninum infection in a lamb.J. Parasitol 76:127, 1990.


Neosporosis

27. Dubey JP, Hattel AL, Lindsay DS, et al:Neonatal Neospora caninum infection in dogs: Iso-lation of the causative agent and experimental trans-mission. J Am Vet Med Assoc 193:1259, 1988.

28. Dubey JP, Janovitz EB, Skowronek AJ. Clini-cal neosporosis in a 4-week-old Hereford calf. VetParasitol 43:137, 1992.

29. Dubey JP, Koestner A, Piper RC. Repeatedtransplacental transmission of Neospora caninumin dogs. J Am Vet Med Assoc 197:857, 1990.

30. Dubey JP, Leathers CW, Lindsay DS.Neospora caninum-like protozoan associated withfatal myelitis in newborn calves. J Parasitol 75:146,1989.

31. Dubey JP, Lindsay DS. Neospora caninuminduced abortion in sheep. J Vet Diagn Invest 2:230,1990.

32. Dubey JP, Lindsay DS, Anderson ML et al.Induced transplacental transmission of Neosporacaninum in cattle. J Am Vet Med Assoc 201:709,1992.

33. Dubey JP, Miller S, Lindsay DS, et al:Neospora caninum- associated myocarditis andencephalitis in an aborted calf. J Vet Diagn Invest2:66, 1990.

34. Dubey JP, Porterfield ML. Neospora caninum(Apicomplexa) in an aborted equine fetus. J Para-sitol 76:732, 1990.

35. Jardine JE, Last RD: Neospora caninum inaborted twin calves. Journal of South Africa Veteri-nary Association 64:101, 1993.

36. Jerret IV, McOrist S, Waddington J, et al: Diag-nostic studies of the fetus, placenta and maternalblood from 265 bovine abortions. Cornell Vet 74:8,1984.

37. Lindsay DS, Dubey JP. Immunohistochemi-cal diagnosis of Neospora caninum in tissue sec-tions. Am J Vet Res 50:1981, 1989.

38. Lindsay DS, Dubey JP, Cole RA, et al:Neospora-induced protozoal abortions in cattle.Comp Cont Ed Pract Vet 15:882, 1993.

39. Lindsay DS, Speer CA, Toivio-Kinnucan MA,et al: Use of infected culture cells to compare ultra-structural features of Neospora caninum from dogsand Toxoplasma gondii. Am J vet Res 54:103, 1993.

40. McCausland IP, Badman RT, Hides S, Slee KJ:Multiple apparent Sarcocystis abortion in fourbovine herds. Cornell Vet 74: 146, 1984.

41. Nietfeld JC, Dubey JP, Anderson ML, et al:Neospora-like protozoan infection as a cause ofabortion in dairy cattle. J Vet Diagn Invest 4:223,1992.

42. Obendorf D and Mason R. Neospora can-inum infection detected in a bovine aborted foetus.Aust Sac Vet Path Report 28:36, 1990.

43. Ogino H, Watanabe E, Watanabe S, et al.Neosporosis in the aborted fetus and newborn calf.J Comp Path 107:231, 1992.

44. O’Toole JM, Jeffrey M. Congenital sporozoanencephalomyelitis in a calf. Vet Rec 121:563, 1987.

45. O’Toole D, Jeffrey M, Challoner D, et al:Ovine myeloencephalitis-leukomyelomalacia asso-ciated with a Sarcocystis-like protozoan. J Vet DiagnInvest 5:212, 1993.

46. Otter A, Griffiths IB, Jeffrey M: BovineNeospora caninum abortion in the U.K. (letter) VetRec 133:375, 1993.

47. Pare’ J, Hietala SK, Thurmond MC. Pre-colostral titers to the Neospora-like agent in dairycalves and effect of congenital infection onpreweaning health. (Abstract) Conference ofResearch Workers in Animal Diseases, Chicago, 52,November 1993.

48. Parish SM, Maag-Miller L, Basser TE, et al:Myelitis associated with protozoal infection in new-born calves. J Am Vet Med Assoc 191:1599, 1987.

49. Rogers DG, McCullough MS, Shain WS, etal. Endemic protozoal abortions in a dairy cow herd.Agri-practice 14:16, 1993.

50. Shivaprasad HL, Ely R, Dubey JP. A Neospora-like protozoan found in an aborted bovine placenta.Vet Parasitol 34:145, 1989.

51. Thilsted JP, Dubey JP. Neosporosis-like abor-tions in a herd of dairy cattle. J Vet Diagn Invest1:205, 1989.

52. Thornton RN, Thompson EJ, Dubey JP.Neospora abortion in New Zealand cattle. NewZealand Veterinary Journal 39:129, 1991.


53. Thurmond, MC, Anderson ML, Picanso J: Esti-mation seasonality of bovine protozoal abortionwith a variable and unknown population at risk.(Abstract) 72nd Annual Meeting of the Conferenceof Research Workers in Animal Diseases, Chicago,November 11-12, 1991.

54. Vickers M, Brooks HV: Suspected Sarcocys-tis infection in an aborted bovine foetus. NZ Vet J31:166, 1983.

55. Woods LW, Anderson ML, Swift PK, SverlowKW. Systemic neosporosis in a California black-tailed deer (Odocoileus hemionus columbianus). JVet Diagn Invest 6:508-510, 1994.

56. Wouda W, Visser IJR, Van Knapen F: Bovineprotozoal abortion (letter) Vet Rec 130(13:279,1992.


notes

Neosporosis

“The milking system is the most important equipment a dairy farmer owns. It “harvests” the cash crop - milk. It comes into intimate contact with every cow two or more times a day, It‘s used 365 days of the year - no matter what the weather, and even when the calendar says it’s a holiday”.

3). Higher incidence of teat-end rings, or ever-

4). Higher risk of new mastitis infections. Here’s a brief summary of the evidence for, and

implications of, these changes. Response to Premilking Manual Stimulation: Pre-

sent-day, high-producing Holstein-Friesian cows appear to need little or no manual stimulation to

hat‘s the introduction for a new booklet, maximize milk production. Although no data have “Maximizing the Milk Harvest” published by been published for cows producing 20,000 Ibs. milk T the Milking Machine Manufacturers Coun- or more per year, all of the available evidence from

cil (MMMC, 1993). This excellent booklet is a studies with lower producing cows indicates that revised edition of the long-running series published high producers are relatively easy to stimulate and by the MMMC. It has been revised completely that oxytocin half-life is unlikely to be a limiting fac- because, in the last five years, remarkable changes tor (see review by Mein and Thompson, 1993). have occurred in our knowledge and understand- Therefore, the basis of good premilking udder prepa- ing of the milking and cleaning performanceof milk- ration should be to ensure that teat cups are applied: ing systems. To visibly clean, dry teats with meticulous atten-

Recent field studies suggest that large milking sys- tion to detail, to reduce the risk of mastitis and to tems tend to be over-dimensioned and under- maintain top quality milk. designed. New system evaluation procedures indi- At or soon after the time of milk ejection, when cate that the performance and energy efficiency of teats become plump with milk. many large milking systems could be improved With minimal time and effort for manual stim markedly by a few simple design changes, and by ulation. more thorough equipment service and maintenance Longer Milking Times: Although peak flow rates programs. and average milking rates tend to be higher in higher

Machine milking is a unique example of a producing herds, it is quite clear that high-produc- mechanical process that requires the willing co- ing cows take longer to milk out. Field studies in operation of an animal for its success. Therefore, England, France and the U.S. (Stewart et al, 1993), let’s start with a brief review of the changing physi- and the simulation studies of Thomas et al (1993) ological characteristics and needs of high-produc- all show remarkably consistent results. On average, ing dairy cows. cows giving 20-25 Ibs. of milk per milking take

The principles for good milking are well known: about 5 minutes to milk, and cows producing 30- cows’ teats should be clean and dry for milking; 35 Ibs. take about 6 minutes. The conclusion: add cows should be milked gently, quickly and com- 1 minutetothe mean milking time per cow for each pletely, with minimal machine stripping or over- 10 Ibs. increase in mean milk yield per milking. milking. However, the ways in which these princi- The combined effects of longer milk-out times ples are applied is changing as milk production lev- and shorter pre-milking prepping times in high-pro- els continue to rise, because high producing cows ducing herds means that for optimum or more effi- have: cient labor utilization milking systems should be

1). Lower pre-milking stimulus requirements than designed with more units per operator. Simulation low producers. studies on parlor performance by Thomas et al 2). Longer milking times (in spite of their higher (1994) indicate that a 10-lb. increase in mean milk

average milk flow rates). yield per cow per milking would reduce the num-

sions.

ber of parlor turns by about 0.7 turns per hour in double-1 6 or double-20 parlors.

Can we adjust the milking machine so that cows producing 40 Ibs. per milking could still be milked out in 6 minutes? The three easiest variables with the greatest influence are vacuum level, pulsation ratio, and the threshold settings on automatic cluster detachers.

It is common knowledge that increasing the system vacuum level, eg. from 13.5 to 15 inches of mercury (“Hg) and widening the pulsator ratio (eg. from 5050 to 6040 or to 7030) results in faster milking times. On the other hand, a comprehensive review of teat tissue reactions to milking indicates that machine-induced teat congestion and edema, incidence of teat lesions and, perhaps, new mastitis infection rates, tend to increase with increasing vacuum level and wider pulsator ratio (/DF 1994).

It seems that we must reach a compromise between machine settings for fast milking and for maintaining healthy teats.

Typically, the system vacuum should be set between 12.5" and 13.5" Hg for lowline milking, and between 14" and 15" Hg for highline milking, according to guidelines in the MMMC booklet (1993). Usually, this will result in a mean vacuum level in the claw within the range 10.5" and 12.5" Hg during peak milk flow for a representative sample of cows. I try to set the system vacuum at the higher end of these ranges so that cows are milked as fast as possible, but still within the range recommended to maintain gentle milking conditions.

Pulsator ratios of 60:40 to 7030 milk cows quickly and comfortably when narrow-bore teat cup liners are used. Because there's less margin for error at wide ratios like 7030, excellent testing and ser-

vice programs are needed to maintain pulsators in top condition.

Pulsation rates somewhere around 50-60 cycles per minute work fine. The small additional gain in milking speed at higher pulsation rates tends to be offset by poorer teat-end condition. Although the system vacuum level could be lowered to com-

milking speed would then be slower! Average milking time per cow was reduced by

0.5 minutes, and teat condition was improved, in a Danish experiment when the threshold setting on the automatic take-offs was raised from 0.44 to 0.9 Ibs. milk per minute (Rasmussen, 1992). Milk yield and milkcomposition were the same for each group of cows. Alternatively, the delay time could be reduced from about 20-30 seconds after the threshold flow rate setting down to 10 seconds. This change would save about 20-40 seconds per parlor turn.

Teat End Condition: Healthy teat skin provides the best defense against all types of pathogens. Fur- thermore, smooth healthy teat skin is easier to clean and easier to keep clean compared with rough or damaged teat surfaces. The act of milking aggravates all types of teat lesions, however. Machine milking is the main cause of teat canal erosion (variously known as teat orifice "eversion", "rings", fibrous rings or epithelial hyperplasia), hemorrhagic blisters near the teat end, and much teat chapping.

A high prevalence of teat end lesions is common in high-producing cows milked by machine,especially in early lactation. The progressive deterioration in teat end condition with increasing 305-day milk yield is shown in Figure 1 on the preceeding page. Less than 9% of teat ends were classed as normal for cows giving more than 18,000 Ibs. milk (305d) (Seiber, 7979). The design and action of the teat cup might need to be modified to maintain the teats of high-producing cows in acceptable condition.

New Mastitis Infections: Cows that milk faster have higher infection risk. Cows with more patent (slack) teat canals also have higher infection risk dur-

ing their dry periods. Thus, high-producing cows may have higher mastitis infection risk because of the indirect relationship between high production, high milking rates, and more patent teat canals (see review by Mein & Thompson, 7993).

Management practices to keep udders clean, such as clipping or "flaming" udders and use of

as pre-milking teat preparation and post-milking teat disinfection, will requiremeticulouscareand attention to detail to minimize the unavoidably higher risk of mastitis in high-producing, fast-milking cows.

Performance Guidelines for Milking Systems A new national standard for the construction and

performance of milking systems was published last year (ASAE S518: 1994). This new ASAE standard is based on a Draft International Standard, DIS/ISO 5707:1994, which has been reviewed and revised extensively during the past 3 years. Both standards incorporate new performance guidelines to provide a common basis for evaluating the great variety of types and sizes of milking systems used throughout the world.

The new performance guidelines for sizing milklines, vacuum supply lines, and vacuum pumps, are based on recent research at the UW-Madison. This research showed clearly that transient vacuum drops of less than 0.6" Hg in milkline or receiver vacuum had little or no effect on the normal cyclic vacuum changes in the milking clusters. Such small transient vacuum changes are completely lost, or over-rid- den, by the larger cyclic changes generated within the cluster by the combined effects of pulsation and milk flow from the cluster.

The new performance guidelines are based on these conclusions: that transient vacuum changes of 0.6" Hg or less in the milkline or receiver are hardly measurable in the claw and have no significant effects on milking characteristics, mastitis, or milk quality.

Why choose an odd value such as 0.6" Hg for a national standard? Firstly because 0.6" Hg is equal to 2 kiloPascals (2 kPa) in the internationally- accepted SI unit of pressure. And, more importantly,

pensate for this more aggressive pulsation action, clean bedding materials, and milking practices such

because vacuum fluctuations in the claw are usually increased whenever the milkline vacuum drops more than 0.6" Hg.

Sizing milklines: Fluid flow in milklines typically varies between "stratified flow" (when milk flows in the lower part of the milkline and air can flow in a clear, continuous path above the milk) and "slug flow" (when intermittent slugs of milk f i l l the entire cross-section of the milkline). Stratified flow is the preferred flow condition to maintain a reasonably stable vacuum supply to the cluster during milking. Slug flow conditions almost always induce a transient drop in milkline vacuum greater than 0.6" Hg. Transient vacuum drops caused by slug flow are characterized by a rapid drop in milkline vacuum below the average stable level in the receiver, and rapid recovery when the slug enters the receiver.

The key performance indicator of stratified flow, therefore, is that milkline vacuum should not fall more than 0.6" Hg below receiver vacuum, at the designed milk and air flow rates, including the transient air flows normally associated with cup changing and liner slips.

New recommendations for sizing milklines

line to ensure that stratified flow is the normal flow condition for milking high-producing cows in parlors or stanchion barn installations, now and into the next decade. It is important to remember that occasional slug flow will occur due to excessive air admission during cup changing or cup falling. Such transient vacuum drops associated with occasional slug flow will have little or no effect on milking performance, mastitis, cell count or milk quality unless they are severe enough to increase the incidence of liner slips and cup falling. The recommendations in Table 1 are for operators who take reasonable care

during cup application and removal. The guidelines in Table 2 are more conservative for more typical operators. The differences between the two Tables

in maintaining a high degree of vacuum stability in the milkline.

Sizing airlines: Differences in vacuum levels between the pump and receiver should not exceed

uum drops, result in decreased air flow reserve at the receiver. Greater vacuum drops are influenced by small line sizes, too many Tees or elbows, or high air flows. Recommendations for sizing the main airline relative to pump capacity, line length and fittings are given in Table 3,

Vacuum fluctuations in the far end of the pulsator airline should not exceed 0.6" Hg. The current 3-A dimensional guidelines seem adequate: that is, 2" for up to , 4 units, 3" for , 5 or more. If 2” line is acceptable up to , 4 units per side, then 3” should be acceptable for up to 32 units based on the sim-

lines could be used for systems with more than 32 units per side.

Differences in vacuum levels between the

Higher readings indicate higher vacuum differences which reduce regulator performance because of

(Tables 1 & 2) are based on this performance guide 0.6" Hg. Higher readings, indicating greater vac-

to limit the amount of air admitted into the system ple ratio of the pipe areas. Therefore, 4" pulsator air-

implies that the milking staff play an important role receiver and regulator should not exceed 0.2" Hg.

either improper location, or excessive restrictions in pipelines and fittings between the receiver and regulator. The most common cause of low regulator efficiency is an excessive vacuum difference between the regulator and the receiver. Regula- tors mounted on branch lines often perform inef- ficiently unless the connecting lines are adequately sized to minimize frictional losses. Branch lines are fine as long as they are sized generously. Guidelines for sizing the regulator branch line are given in Table 4.

Regulators mounted on or near the distribution tank often tend to oscillate of the cyclic vacuum changes in pulsator airlines. Preferably, the regulator (or its sensor) should be connected near the sanitary trap so that it can sense, and quickly respond to, vacuum changes caused by "unplanned" air admission entering the system through the teat cups.

Reserve pump capacity: In 1992, Paul Black- mer (DVM, Veterinarians' Outlet, CA) proposed a practical performance criterion to demonstrate adequate vacuum pump capacity for milking:

Vacuum fluctuations in or near the receiver should not fall more than 0.6" Hg below the intended vacuum level during the course of normal milking (including cup attachment and removal, liner slips and cluster falls). This proposal has been tested by a Task Team

of the National Mastitis Council's Machine Milk- ing Committee. The Task Team has just completed a two-part field study to determine the minimum Effective Reserve required to achieve an acceptable degree of vacuum stability during milking. Before describing the main conclusions and recommendations of the NMC Task Team, here's a brief explanation of the term "Effective Reserve" and some related indicators of the effectiveness of vacuum production and control:

"Effective Reserve" is an airflow measurement of the spare (or "reserve") pump capacity actually available to maintain the receiver vacuum stable within 0.6" Hg when extra air enters the system dur-

ing milking. The test assumes that a vacuum drop of 0.6" Hg is an acceptably small drop which ha! little or no effect on milking performance and which is sufficientto allow the regulator to close. It is mea. sured with:

-All the teat cups plugged and under vacuum.

-The regulator connected and working. - Air admitted into the receiver to drop the

receiver vacuum by 0.6" Hg. The NMC Task Team concluded (Mein et al,

1995) that: 1 , All milking systems should have sufficient

Effective Reserve (ER) to cover the possibility that at least one milking unit might fall off during milking. This implies a minimum ER of 35 cubic feet per minute (cfm) free air for any conventional milking system without automatic shut-off valves in the claw.

2. Larger systems (more than 32 units) should have sufficient reserve to cope with two simultaneous falls even though the likelihood of these events occurring simultaneously seems very low.

3. No system appears to need any more than 120 cfm Effective Reserve.

4. The suggested range of 35 cfm minimum ER and 120 cfm maximum ER will provide adequate reserve for vacuum stability during milking.

5. A simple formula for ensuring generous ER for systems with up to 80 units is: a basic reserve of 35 cfm, plus an incremental reserve of 1 cfm per unit.

"Manual Reserve" is a measurement of the airflow capacity potentially available to maintain the receiver vacuum stable within 0.6" Hg if the regulator could close completely. It is measured with: - The regulator disabled

(put out of action). - All the teat cups plugged

and under vacuum. - Air admitted into the

receiver to drop the receiver vacuum by 0.6" Hg.

In summary: Effective Reserve is measured with the regulator working. Manual Reserve is measured with the regulator disabled. The difference between these airflow measurements is "Regulator Leakage".

Another useful indicator of the effectiveness of the vacuum regulation system is the "Regulator Per- cent Closure" (also known as "Regulator Effi-

ciency"). Ragulator Percent Closure = Effective Reserve X 100

A Regulator Closure of 100% would mean that the regulator can close completely in response to a vacuum drop of 0.6" Hg below the working vacuum in the receiver. A good practical guideline is that Regulator Closureshould be 90% or more. This guideline is the simplest practical indicator of the combined effects of the sensitivity of the regulator, the amount of reserve pump capacity provided, and the effects of airline sizes and other restrictions to air flow between the regulator and the site of measurement.

The efficiency of vacuum regulation can be improved on many installations. Regular cleaning and maintenance of the regulator is an important part of the solution. However, poor regulator performance often results from inappropriate regulator location combined with inadequate airline sizes to cope with excess vacuum pump capacity. The vacuum regulator should be moved and/or airline sizes and pump capacity adjusted to provide an Effective

Reserve of 90% or more of the available Manual Reserve (MR).

Guidelines for pump capacity are desirable for advisors and farmers. Assuming that ER is at least 90% of MR, a simple guideline for estimating the minimum pump capacity would be a basic reserve of 35 cfm, plus an incremental allowance of 3 cfm per unit. Such a guideline would provide enough pump capacity to cover allowances for system leakage, pump wear, and also regula-

tor leakage if the regulator is correctly located and adequately plumbed. However, extra pump capacity might be needed to allow for certain ancillary components during milking and/or washing (Mein et a/, 1995).

These results provide broad support for the simple guidelines for pump capacity which were pub

Manual Reserve

lished by Bray (1992) and which are reproduced as Table 5 for convenient comparison. These guidelines will provide adequate airflow capacity for efficient cleaning of properly designed CIP systems Fig- ure 2, from Reinemann and Mein, 1995).

Compared with current 3-A Accepted Practices, these recommendations would provide higher pump capacity for systems with up to 8-10 units, similar pump capacity for 12 units, and progres- sively lower total pump capacity for systems with more than 16 units (Figure 2).

In the field study conducted by the NMC Task Team, improved system design produced big improvements in the effectiveness of vacuum regulation on most milking systems. Because of the improved regulator performance, the available pump capacity (and, therefore, the Manual Reserve) could be reduced by at least 50 cfm for 14 of the 19 systems, and by more than 100 cfm on nine of these

systems. Thus, significant energy savings were achieved on most farms with no evidence of reduced milking performance for any of the herds. If the cost of electrical energy is 1 0¢ per kWh, then the energy cost for a 10-HP pump running 18 hours/day is over $500 per month Table 4 in Mein et a/, 1995).

An example of the effects of these design improvementson some dimensions, air flow capac- ities and wash water requirements, is given in Table 6 for a Double-24 parlor. There is strong evidence from laboratory research, field studies and experience on a wide range of commercial farms to support a revision of the current national standards for vacuum pump capacity. However, the process of review and possible revision of the 3-A Accepted Practices and ASAE S-518 Standards may take 12 months or more. In the interim, dairy farmers who wish to take advantage of the potential savings in

energy and water use will need to seek permission for such variations from the relevant State regulatory authorities. Furthermore, because most milking equipment suppliers will be reluctant to install systems which do not meet current national standards, the owner should be prepared to sign a waiver that he/she wants a system with lower pump capacity.

Another interim option for large milking systems would be to install 2 pumps which, when run together, meet current 3-A standards and, when only one pump is running, would meet the new minimum requirements for Effective Reserve. If so, the second pump can be used as a stand-by in case of breakdowns.

Testing, Service & Maintenance Of Milking Equipment

evaluation have been developed by a Task Team chaired by Andrew Johnson, DVM, for the National Mastitis Council's Machine Milking Committee. In addition, a systematic visual check can indicate the milking machine faults likely to be associated with mastitis or teat condition problems, or with slow or incomplete milking. Guidelines for the three best indicators of machine function during milking are given in the 1992 NMC proceedings (Mein, 1992). They are:

The condition of teats when cups are removed. The completeness of udder evacuation.

The most common reason for milking system problems in the 1990's is inadequate routine maintenance of milking equipment. The booklet "Maxi- mizing the Milk Harvest" (MMMC, 1993) makes a

simple analogy: "A car driven at 60 mph for 10 hours per day will travel more than 200,000 miles in one year. Milking equipment, like the car, has many moving parts that wear over a period of time." The lack of down-time for maintenance in large dairies, combined with the lack of awareness of the

20 hours per day results in a poor level of maintenance on many farms.

The MMMC booklet gives simple, clear guidelines for maintenance of milking and cooling systems. All milking machine companies and most milking equipment dealers have similar guidelines and most of them w i l l provide service contracts for scheduled maintenance. Starting in 1 990, member compnies of the MMMC have developed a certi- fication Program for their technical staff and dealers to ensure that training courses conducted by individual companies contain the same minimum

include specialized training in the new conceptsfor improved system design and performance outlined in this paper.

With improved system design, some of h e poten-

Excellent new procedures for milking system gradual deterioration of components used for 10 or

The frequency Of slipping or falling teat cups. requirements. These training courses will, or should,

tial savings from reduced energy costs, water and cleaning chemical costs could be invested profitably in more thorough routine maintenance of equipment and facilities. That would be a “win-win” for all participants: dairy farmers, milking staff, equipment manufacturers and dealers, and for the cows!

Making ManureNutrient

ManagementWork For You

By Deanne MorseLivestock Waste Management Specialist,

Animal ScienceDavis, CA 95616

916-752-9391fax 916-752-0175

By Lawrence SchwanklIrrigation Specialist

LAWRDavis, CA 95616


CC rop nutrient management is not a new idea.In fact, the concept dates back quite a fewyears. The idea is being revisited by dairy

producers for two key reasons. The first is econom-ics. It costs money to purchase and apply nutrients(fertilizer) for crop needs. The second reason to re-visit crop nutrient management is the potential con-tribution of manure nutrients to ground or surfacewater contamination.

It is important to realize that nutrient manage-ment assumes a few points. One area relates to theapplication of nutrients. It is assumed that nutrientsare applied at the appropriate time with respect togrowth and development of the plant. It is assumedthat nutrients are applied in a form available to theplant. Some forms may be more readily availablethan others. It is assumed that the appropriateamount of nutrients is applied. The second categoryof assumptions deals with the location of the nutri-ents. It is assumed that the nutrients are appliedwhere needed. It is assumed that the nutrients arenot leached beneath the root zone of the plant. Thislast assumption requires consideration of irrigationwater management.

The areas of manure nutrient management con-sidered here include: how to sample manures, whatto do with the laboratory results, consideration of ir-rigation uniformity and efficiency, and how todevelop a farm nutrient management plan.

Sampling LiquidsKnowledge of your pond nutrient content is the

first step in making liquid manure nutrients worksfor you. The nutrient content of water in a dairy ponddepends on the number of animals contributing tothe pond, the presence or absence of a solids sepa-rator, the amount of fresh water added daily, and theamount of manure collected from each animal.

There is no rule of thumb to account for the nutri-ents in manure waters. In fact, data from the west-ern states indicate large variations in nutrient con-tent of manure waters. Total nitrogen in an acre-inchof water was 28 lbs from one pond and 228 lbs.from another pond (Morse & Schwankl, 1995). Asimilar comparison from multiple ponds sampled in

Idaho indicated average total nitrogen to be 83+60lbs per acre-inch of water (Ohlensehlen et al., 1993).

It is critical to sample pond water to more closelyestimate nutrient content. Sampling containersshould be clean and dry. A sample should be morethan a pint and less than a quart. Water should beflowing for at least 10 minutes before sampling. Fillthe container about two-thirds full. Freeze the sam-ple immediately after sampling. The empty air spacein the container will allow the water to expand with-out breaking the container. Check with your ana-lytical laboratory to determine the proper samplesize, and particular handling practices for the sam-ple. Labs may have sample containers for use.

It is easiest to sample water as it comes out of thepond and drops into the irrigation system standpipe.In fact, it is more precise to estimate nutrient con-tent from manure water leaving the pond than it isto sample water in the pond. In some instances, itis not easy to access manure water as it enters astandpipe. If that’s the case, sample manure wateras it enters crop fields. When sampling at an irriga-tion valve (instead of a standpipe) it is important tolet debris in the pipeline pass through, and to besure the water being sampled is full strength manurewater (not diluted).

Manure water should be analyzed from a pondduring the spring dewatering. These waters can bedifferent than waters used during the summermonths. The results of samples taken on the sameday are similar. Yet, results of samples taken on dif-ferent days are quite different. At this time, the rec-ommendation is to sample the manure water everyother day during the spring dewatering. The aver-age of the results should be used to estimate nutri-ent content of manure water.

Additional samples should be taken at least twiceduring the summer irrigations. If irrigation water isadded to the pond, further sampling is recom-mended. This will improve the precision of esti-mating the nutrient content of the manure water. Forinstance, the nutrient content of the pond is reduced(diluted) when irrigation water is added.


Making Manure Nutrient Management Work For You

Sampling SolidsThe number of samples need-

ed to estimate the nutrient con-tent of solid manure depends onthe amount and variability of themanure. Similar nutrient contentof manures will come from ani-mals of similar dietary nutrientintake. The nutrient content ofmanure from growing heifers,lactating cows and dry cows willdiffer. Also, the nutrient contentof solids from a solid separatorwill be much different than thenutrient content of corral scrapedmanure. The important part ofsampling is that the sample represent the source.

Using Laboratory ResultsOften liquid samples are analyzed for total nitro-

gen, ammoniacal nitrogen, phosphorus, potassium,and salt (if a concern). All nutrients present are notreadily available to plants. Phosphorus, potassiumand salts are usually in a plant available form.Ammoniacal nitrogen (NH4-N) can be rapidly con-verted to nitrate (NO3) in the soil. Nitrate is the plantavailable form of nitrogen. In this sense, ammonia-cal nitrogen is a fast release nitrogen and organicnitrogen is a slow release nitrogen source. The totalremaining organic nitrogen can be converted toNO3 over time (usually years). Also, the NH4-N canbe volatilized into air as ammonia. The percentvolatilized depends on air and soil temperatures,soil conditions, amount of standing water, windspeed, and pH of the material. Few researchers aremeasuring the percent of nitrogen volatilized fromland applied manure waters. It is assumed that 10%of NH4-N is volatilized during land application witha range between 5 and 25%.

Some elements on a lab report are reported inunits of parts per million. Parts per million can beconverted to pounds per acre-inch of water by mul-tiplying the value by .2268. Elements expressed aspercentages can be converted to pounds per acre-inch of water by multiplying the value by 2268.

Some nutrients (calcium, magne-sium, sodium, chloride) may beexpressed as milli-equivalents.These need special conversionfactors. The laboratory supplyingthe analysis can assist you withappropriate conversions.

The next step is to calculatemanure water flow. After that, itis a simple conversion to go frompounds per acre-inch of water topounds per acre of field. Pump-ing rate of the manure water mustbe known.

Determining pumping rate iseasier said than done. Usual farm

pump tests seldom include checking manurepumps. One challenge of getting a manure pumptest done is the fact that manure water isn’t cleanand therefore it dirties the individual attempting toinstall a metering device. Also, manure water hasdebris (straw, leftover feed, gloves, etc.) that will cloga typical propeller or turbine flow meter.

A non-invasive doppler meter can be used tomeasure flow rates. A sensor is strapped to the out-side of the pipe and an ultrasonic signal is passedthrough the pipe. The signal is reflected by sus-pended particles in the fluid and the frequency shiftin the signal is used to determine the velocity of theflowing liquid. Flow rate can then be calculated withthe flow velocity and the pipe size. These meters areexpensive, but may be owned by someone at theirrigation district, the electric company, or at yourCooperative Extension Office. Pump testing ofmanure ponds should be done when the pond is atvarious depths as the depth of water in the pondalters the pumping rate.

It’s easy to calculate nutrient flow after the sam-ple results are received from the lab and the pumptest results are known. The calculation is as follows:

nutrients applied = nutrient content X water applied(lbs applied) (lbs/ac-in) (acre-inches)


It is more preciseto estimate

nutrient contentfrom manure wateras it comes out of

the pond anddrops into the irri -

gation systemthan it is to

sample water inthe pond.

Water applied can be calculated by multiplyingthe flow rate (gallons/minute) by the amount of timethe water flowed (number of minutes) divided by27,154 gallons per acre-inch of water. For a pumpthat discharges 300 gallons/minute the calculationfor 2 hours (120 minutes) is 300 X 120/27154 = 1.3acre-inches. The nutrients entering the field aredivided by the amount of acres to determine thepounds of nutrients applied per acre of cropland.

An example of nutrients (pounds) applied to afield during a one-hour irrigation are in Table 1. After1 hour of pumping with a 100 gallons per minutepump, and a nutrient content of 100 parts per mil-lion, 5 pounds of the nutrient entered the field. If thepump rate was 500 gallons per minute and the nutri-ent content was 100 parts per million, then 25 lbsof nutrients would enter the field. Note: these cal-culations are for a pump working 1 hour. Most irri-gations are more than 1 hour.

Results from solid manure samples are similar toforage test results. Moisture and percentages of eachelement will be listed.Total nitrogen will be re-ported. Unless request-ed, ammoniacal nitro-gen will not be reported.A useful calculation is todetermine the amount ofnutrient applied per tonof wet manure applied.

Irrigation EfficiencyAnd Uniformity

Once nutrient content(lab analysis) and appli-cation rate (pumping ratefor liquids, spreading rate for solids) are known, thenext step is to determine where nutrients are going.Nutrients in manure water follow the water flow.Although a considerable amount of solids can set-tle out during an irrigation, nutrients don’t settle out(Morse et al., 1994).

It is important to identify how much and wherewater goes during an irrigation. Irrigation waterapplied to a field can end up in one of three loca-tions. The desired location is for water to be stored

in the crop’s root zone. Storing water in the crop’sroot zone is the normal objective of an irrigation.Irrigation water can run off from the field surface.Tail water return systems can be used to capture sur-face runoff and reuse it. Other surface runoff is ille-gal in California. Another location where water mayend up is below the crop’s root zone. Excess waterresults in deep percolation. Both water and nutri-ents move beneath the crop’s root zone. Nitrate isvery mobile in soil and moves with the deep per-colating water front. These losses are undesirable asmore water is used than needed and leached nutri-ents may contaminate groundwater.

Irrigation efficiency describes how much of theapplied irrigation water is stored in the crop’s rootzone. This number expresses the amount of waterused by the plant as a percent of the water applied.The formal definition of irrigation efficiency (IE) is:

Irrigation Efficiency = water beneficially used X 100(IE-%) water applied

Beneficially used water is the amount of waterneeded to refill the crop’sroot zone. This amount ofwater is equal to the soilmoisture used by the cropsince the last irrigation. Irri-gation scheduling tech-niques can be used to deter-mine the irrigation amountrequired. These techniquesinclude determining plantevapotranspiration (ET)and/or soil moisture moni-toring. For instance, if thelast irrigation was 10 days

ago, ET estimates may indicate that the crop used 2.5inches of water (0.25 inches/day x 10 days = 2.5inches). The objective of irrigating would be to apply2.5 inches of water to refill the crop’s root zone.

Irrigation Application UniformityWater application uniformity describes how

evenly water is applied to the field. If every part of



Table 1. Amount of nutrients applied to a field (pounds) basedon nutrient content of water (parts per million-ppm) and pumprate (gallons per minute-gpm). This assumes the pump ranfor 1 hour.

nutrientcontent (ppm) 100 gpm 300 gpm 500 gpm25 1 4 650 3 8 13100 5 15 25150 8 22 38200 10 30 50250 13 38 63300 15 45 75

the field received the same amount of irrigation water, the irrigation would be 100% uniform.

Distribution uniformity (DU) is commonly used to quantify uniformity in furrow and border irrigation systems. It is defined as:

cussed previously. The contribution of clean irrigation water can be determined. Pump test results from a well can be used to estimate flow rates. Realize these estimates can lead to errors as changes in pump performance, pumping depth, etc. can change pump rate. A more precise method of determining well water flow rate is to use an in-line meter (e.g. propeller meter). Additionally, flow rate should

Interactions Between Irrigation Eillciency And Uniformity

tion efficiency and uniformity is the key to understanding@ irrigation water management, It is not possible to adequately irrigate a field efficiently (the appropriate amount of water) unless the water is applied uniformly. However, irrigating uniformly will not guarantee that the irrigation is efficient.

. .

be for canal water. average applied

The depth of water applied to the low 1/4 of the Understanding the relationship between irriga- field is the depth of water applied to the 25% of the field which receives the least water. For furrow-irrigated fields, this is usually the 25% of the area at the tail end of the field.

Irrigation water application rate should be determined. Measuring manure water quantities was dis-

(1) the irrigation water nutrient concentration;(2) the chemical form of nitrogen in the irrigation

water;(3) soil characteristics such as permeability, poros-

ity, and texture; and(4) soil nutrient levels prior to irrigating. Informa-

tion is not available currently to predict the nutrientcontent of deep percolating water resulting from asingle irrigation event.

Management MeasuresTo Improve Irrigation Practices

The following scenarios illustrate the combina-tions of irrigation efficiency and uniformity. Man-agement alternatives are provided to reduce the riskof contaminating groundwater. Each of these sce-narios has a potential impact on groundwater qual-ity. The extent of contamination will depend on theamount of deep percolation and the nutrient con-tent (e.g. nitrate). The fourth combination – goodefficiency and good uniformity – is the desired irri-gation event. A summary of management alterna-tives to minimize groundwater contamination is inFigure 1 on the preceding page.

Irrigation Uniform But InefficientScenario 1 is an irrigation which is uniformly

applied, but is inefficient. In this case, the irrigationsystem is performing acceptably. Water is uniformlydistributed. However, water is not used efficiently.Irrigation scheduling is not being practiced and/orwater quantity is not being measured. Excess irriga-tion water is being applied. Over applied water willresult in deep percolation. Both soil and manurewater nutrients can move downward with the deeppercolating irrigation water.

Irrigation efficiency can be improved to decreasethe amount of deep percolation. One method toimprove efficiency is to decrease the amount ofwater used in an irrigation. Another method is toincrease the interval between irrigations. Either alter-native should more closely match the soil moistureused since the previous irrigation. Usually, it is morepractical to increase the interval between irrigations.Frequently a minimum amount of water must beapplied for the water to advance across the field. Analternative management technique may be to match

the minimum water application amount with thecorresponding irrigation interval. Crop water usewould be equivalent to the irrigation amountneeded to advance water across the field.

A fourth alternative to improve irrigation effi-ciency is to collect and reuse tail water runoff fromthe field. Tail water return systems allow use of largeflow rates and can help ensure that the tail of thefield is adequately irrigated. The adoption of irriga-tion techniques to avoid tail water runoff – smallflow rates, long field lengths, etc. – can lead to inef-ficient and non-uniform irrigations. Substantial deeppercolation at the head of the field is a commonresult, and inadequate irrigation at the tail of the fieldis also common.

Irrigation Efficient But Non-UniformScenario 2 is an irrigation which is efficient but

non-uniform. On the average, the correct amountof water is applied to the field (it’s efficient). Forexample, if 3 inches of water have been depletedfrom the soil profile by crop water use, for each acreirrigated, 3 acre-inches of water would need to beapplied. For furrow irrigation, the non-uniformityusually results in the head of the field being over-irrigated while the tail of the field is under-irrigated.The over-irrigation (inefficient) at the head of thefield would produce deep percolation. The deeppercolation could move soil and manure waternutrients into underlying groundwater. Thus, eventhough on the average the correct amount of waterwas applied, the application non-uniformity wouldresult in deep percolation. The irrigation systemapplication uniformity must be improved in orderto adequately irrigate the entire field while irrigat-ing efficiently. Alternative practices to improve uni-formity are included in the next section.

Irrigation Inefficient And Non-uniformScenario 3 is an irrigation which is inefficient and

non-uniform. Such an irrigation results from excessuse and uneven distribution of water. This scenarioholds the greatest potential for deep percolation andcontamination of underlying groundwater.

This scenario occurs when the field length is toolong to irrigate uniformly. Also, irrigations on soils



George Brandsberg

Potential of contaminating groundwater by deep percolation from manure water irrigations will be affected by:

with poor water holding capacity are often ineffi-cient and non-uniform. Only a small amount ofwater per irrigation is needed to refill the crop’s rootzone. Such conditions exist when sandy soils areirrigated. Such soils don’t store much water andneed small yet frequent irrigations.

The major criterion for determining irrigation settime is the amount of time it takes to get water tothe end of the field (advance time). The minimumdepth of water which can be applied per irrigationis controlled by the end-of-field advance time. Forexample, if corn irrigations are at 10-day intervals,the irrigation objective may be to apply 3 inches ofwater during the irrigation. This objective wouldresult in an efficient irrigation. The length of the fieldrequires application of a minimum of 5 inches ofirrigation water simply to advance water to the endof the field. The result is an irrigation event whichis inefficient (over-irrigated).

Irrigation non-uniformity is a result of the differ-ent lengths of time water is in contact with the soil(infiltration time) at various parts of the field. Forexample, a typical, 800-foot, furrow-irrigated fieldmay require 8 hours to advance water to the end ofthe field. The irrigation water is shut off when itreaches the end of the field. Water therefore infil-trates for 8 hours at the head of the field and for onlya few minutes at the tail of the field. This differencein infiltration time results in significantly more watersoaking into the soil at the head of the field than atthe tail of the field. Irrigation non-uniformity is theresult of such an irrigation.

Furrow and border irrigation often suffer fromsuch an irrigation non-uniformity problem. Therewill always be a difference in infiltration timebetween the head and tail of the field resulting fromthe time it takes to advance water across the field.Shorter field lengths have lesser infiltration time dif-ferences between the head and tail of the field. Thisresults in better irrigation uniformity.

Alternative management practices can improvethe irrigation system’s application uniformity. Phys-ical changes require capital expenditures. The costsand benefits (water and nutrient conservation) needto be evaluated for each alternative. The following

alternative practices may be used to improve appli-cation uniformity.

• Change the field slope. Increasing the slope ofa field will cause water to advance across the fieldmore quickly. This will reduce the time water isallowed to infiltrate at various field locations.

• Increase the water flow rate to the field. Thiswill result in faster water advance across the fieldand reduce the time water is allowed to infiltrate.

• Reduce deep ripping of the field or alter sea-son of deep ripping. Deep ripping prior to fieldpreparation and irrigation results in an increasedinfiltration rate and a slower water advance timedown the field. The slower water advance results ingreater irrigation non-uniformity. Eliminating deepripping altogether or minimizing its use can reducethe severe irrigation non-uniformity problems oftenexperienced during the pre-irrigation and early sea-son irrigation events. There is no capital cost asso-ciated with reduced deep soil ripping.

• Use furrow torpedoes. Furrow torpedoes areweighted steel cylinders, 6 to 12 inches in diame-ter and up to 4 feet long. Torpedoes are dragged infurrows to break up soil clods and smooth the fur-row surface. They are most effective when used priorto the pre-irrigation or following field cultivation.The result is more rapid irrigation water advanceand improved irrigation uniformity.

• Use surge irrigation. Surge irrigation is turningwater on and off as it flows down the field. Water isallowed to flow down the field for a given distance.The flow is stopped until the water in the furrowrecedes. The water flow is restarted. This can resultin less water being used to advance the irrigationwater to the end of the field. During the off-time, theflow can be diverted to other parts of the field. Thesecond water surge wets both the previously wet-ted length of the furrow and an additional sectionof dry soil. This procedure continues until waterreaches the end of the field. Use of surge irrigationcan improve the irrigation application uniformity aswell as the irrigation efficiency. While surge irriga-tion can be done manually, automation requires asurge valve and gated pipe.


• Reduce the field length. This isthe most effective step which can betaken to improve irrigation unifor-mity, but it is also very expensive. Thecosts, such as new supply pipelineand re-leveling, can make reducingfield lengths impractical.

Nutrient Management ProgramTwo final pieces of information are needed before

a nutrient management plan can be developed. Soilnutrient content and estimated plant nutrient useshould be known. The number of soil cores neededto determine soil nutrients depends on field vari-ability. Contact the local Cooperative Extension Of-fice or Natural Resource Conservation Service (for-merly the SCS) for advise on soil sampling. They canalso aid you in determining the depth of the sam-pling. Certainly, one needs to sample through thedepth of the crop root zone. You may chose to havesoil samples taken by a private lab.

Plant nutrient use can be determined in one oftwo ways. One method is to determine the amountof nutrients harvested the previous cropping season.This is easy to do when a forage crop was grownand harvested. Yields and nutrient content wouldbe available. Another method is to use recom-mended nutrient requirements for crops where allthe plant matter isn’t harvested, or it is harvested butnot analyzed for nutrients. Nutrient needs of cottonor cereal grains are best determined from local dataor standard tables for your county or state.

Now actual nutrient management plan can bedeveloped. For each field, the following calcula-tions should be made. Amounts of nitrogen, phos-phorus and potassium needed by the plant and pre-sent in the soil should be estimated. By difference,the approximate amount to apply is calculated. Theactual amount of nutrients supplemented may bemore than what is calculated. This would allow fornitrogen lost to the atmosphere that is not availableto the plant.

If line 3 is greater than 0, then the land can acceptmanure nutrients. Other items to consider in a nutri-ent management plan include when to apply nutri-

ents, soil nutrient and water holding capacity, andsoil type.

Realize that if manure nutrients are applied tomeet the nitrogen needs of a crop, phosphorus,potassium and salts are usually over applied. Thiscan lead to an undesirable buildup of salts in thesoil. Although deep percolation is a standard prac-tice to remove excess salts from the crop root zoneit will result in salts leaching into the underlyinggroundwater. Also, phosphorus is not easily leachedthrough the soil, but can be a concern related to sur-face water quality. Phosphorus enters surface waterswhen soil is eroded.

Additional nutrients needed can be obtainedthrough a variety of sources: irrigation water, manurewater, solid manure, other soil amendments or com-mercial fertilizer. The application rate of manurenutrients should depend on the nutrients needed. thesoil nutrient needs should be used to determine if theland can accept manure nutrients and at what ratethe nutrients can be applied. Once this is calculated,then the manure application rate is determined.

The limiting nutrient to determine manure appli-cation rate will vary. If surface water concerns exist,phosphorus usually limits application rate. Ifgroundwater concerns exist, nitrogen or salts maydetermine application rate.

Producers who live on poor soils and have highwater tables must be particularly careful with nutri-ent applications. Such locations are more suscepti-ble to groundwater contamination. Excessive irri-gation water use can be detrimental. Both nutrientmanagement and water use must be managed toprevent contamination of groundwater.

The biggest question arises when nutrient man-agement plans are developed and it is evident thatinsufficient land exists to utilize manure nutrients.When this occurs there are other alternatives. The



Tons N P K(lbs/acre)

1. Est. crop yield _____ ___ ___ ___2. Avail soil nutrient contribution ___ ___ ___3. Add’l nutrients needed (line minus line 2) ___ ___ ___

appropriate combination of alternatives will dependon the magnitude of the extra nutrients and whichnutrients are excessive.

A successful nutrient management plan will mon-itor nutrients applied to soil as well as nutrient move-ment through the soil. Irrigation water managementis a critical element to nutrient movement in the soil.

References:1. Merriam, J.L. and Jack Keller. Farm Irrigation

System Evaluation: A Guide for Management. UtahState University. 1978.

2. Morse, D., L. Schwankl, T. Prichard and A. VanEenenaam. 1994. Evaluation of manure water irri-gation. Environmentally Sound Agriculture. Pro-ceedings of the Second Conference. April 20-22.Pp. 353-360.

3. Morse, D. and L. Schwankl. 1995. Land appli-cation of manure waters: nutrient content. Pro-ceedings of the 1995 California Plant and Soil Con-ference. January 10, 11. Pp. 142-147.

4. Ohlensehlen, R.M., D.E. Falk and M.V.Boggess. 1992. Waste Characterization of 21 South-ern Idaho dairy lagoons. J. Dairy Sci. 76(suppl):257.

5. Schwankl, L.J. and D. Morse. 1995. Land appli-cation of manure waters: irrigation uniformity andefficiency considerations. Proceedings of the 1995California Plant and Soil Conference. January 10 -11, 1995. Pp. 147-152.

6. Schwankl, L.J., B.R. Hanson, and S. Panoras.1992. Furrow torpedoes improve irrigation wateradvance. California Agriculture. Vol. 46, No.6.

7. USDA, Soil Conservation Service. 1986. SurgeIrrigation. Nat. Engr. Notice No.5.

2ND WESTERN LARGE HERD DAIRY MANAGEMENT CONFERENCE • LAS VEGAS, NV • APRIL 6-8, 1995 ? ?

notes

George Brandsberg

87


notes

Freestall Housing Guidelines: Design Details To Enhance

Management

well planned housing design provides the aged and handled in groups. These groups are dairy herd with good access to feed and moved to, through and from the milking center two A water, a clean, dry, comfortable resting area, or more times per day. However, individual COWS

and good ventilation during all seasons. Whether must be separated from the group regularly for one group or a dozen, good system planning sim- breeding, treatment or special observation. While plifies the process of milking, animal handling, feed Cows are in the housing area they must have con- delivery and manure collection so that these tasks venient access to feed, water and the resting area. may be performed properly and consistently. Good Each COW group should be moved to and from design can save time, minimize the amount of labor the milking center at a comfortable, easy pace, with- required and reduce drudgery and frustration. This out excitement or unnecessary force, safely, by one paper will focus on design details that enhance COW person. In addition, the means to isolate and restrain comfort and make the movement of animals, feed, an individual COW for special care should be pro- and manure more convenient in dairy freestall hous- vided to the handler- ing using fenceline feeding. Grouping

Clean, healthy, high producing cows require four basic things from the housing area:

Dividing the milking herd into groups allows for better management. Grouping can simplify animal movement, make observation easier, and allow feed rations to be adjusted to fit the group's needs. Group- ing of the milking herd is often done according to production, stage of lactation, or age.

The holding area should be large enough to confine each group so that cows do not have to be sorted, or enter the holding area in shifts. Sizing the holding area 25% larger allows another group to be moved into the holding area behind the crowd gate just before the other group is finished milking.

Group size is influenced by the capacity of the milking parlor. Armstrong (1993) suggests that cow groups milked two, three) and four times per day should be milked in 60, 45. and 30 minutes per group, respectively. This recommendation is based on the stress associated with a closely confined group of COWS, especially in hot weather. Being away from feed and water for a long period of time is also a concern

Albright (1983) suggests that group size remain stable and no larger than 100 COWS- Each group should be identified clearly by name or number. This can be accomplished with a sign and/or blackboard located for convenient observation. Identification and information should be presented in a way that new/temporary employees can understand easily.

Traffic lanes And Patterns

I ) . Clean, dry comfortable resting area. 2). Good air quality 3). Good access to (and a supply of) feed. 4). Good access to (and a supply of) warer.

Most other things done in the design of dairy housing are done for the manager, such as:

1). Simple animal handling and observation. 2). Simple anrmal isolation and restraint. 3). Easy feed delivery 4). Easy waste collection and removal.

The designer should not compromise the cow's requirements in the layout of a housing system. Careful attention to cow comfort is necessary for good production, animal health, and to promote cow cleanliness.

Of course, the building should be located on a relatively level, welldrained site with a good source of potable water. Access for feed delivery and milk hauling should be convenient. Service roads around the dairy system should be suitable for traffic at all times of the year. Animal housing and manure storage areas should be located downwind and at a reasonable distance away from the residences to reduce odor and insect concerns. Allow adequate space for expansion. Assume that the dairy system will double in the future.

Animal Handling And Movement Freestall housing systems allow cows to be man-

Making group movement and traffic patterns simple, with a minimum of turns and direction, changes will reduce frustration and excitement. Remember that given the chance, a cow will usually go the wrong way (Graves, 1986). The skill level and tem- perament of cow handler(s) should also be considered.

Traffic lanes between the housing area and milking center should have a well drained, non-skid surface which provides confident footing for cows during all types of weather. Lanes should not slope more than 6% in the direction of cow flow.

Traffic lanes should be wide enough to accommodate the group being moved. Traffic lanes should be 12'-16' for groups less than 150 cows and 20' wide for groups of 150 cows or more (Welchert, 1992).

The movement of one cow group must not interfere with another. Layouts which require one group to pass through the housing area of another group are not desirable. These arrangements may save

building space, but animal movement is usually more complicated, and a group may be restricted from the resting and/or feeding area(s) for a long period of time.

Traffic lane arrangements which allow a group of cows to move to the milking center while another is returning is preferred. Cows tend to linger on their trip back to the housing area from the milking center. Frustration may be increased, and animal movement is delayed, if the cow handler must chase cows out of the traffic lane before the next group can be moved. A second traffic lane allows the handler to briefly close the return lane(s) from the milking center and move the group into the holding area.

Figure 1 shows one layout for freestall housing with four groups. With proper gating, two traffic lanes near the middle of the building allow two groups to be moved without interfering with one another. Cattle guards and/or automatic gates can be used where animals and vehicle traffic cross.

Another layout alternative which provides sim-

ple cow movement is described in Figure 2. Groups are simply moved to, through, and from the milking center in a circular pattern.

Cow Alleys Within The Housing Area The alleys in the housing area should allow the

cows to move freely between the feeding, watering, and resting areas without interfering with other animals. Preferred alley widths at various locations in the housing area are shown below.

that provides confident footing reduces the chance of serious injury caused by slipping and falling. Cows are also more likely to mount and show signs of heat in a housing area with a good, non-skid floor surface.

Grooving is a common method for creating an acceptable floor surface. Grooves should be approximately 3/8-1/2" wide and 3/8"-1/2" deep. The preferred pattern is a diamond shape where the grooves are placed 6"-8" on center. Parallel grooves 2"-4" on center are also commonly used in scrape alleys, traffic lanes and holding areas. Grooves should not run perpendicular to the direction of scraping.

Before animals are allowed onto the surface all sharp edges, or 'wickers', should be removed by chipping or grinding. If the surface is comfortable

Animal Movement Within The Croup

Cows within a group should be allowed easy and convenient access to the feeding area, resting area and water. More study needs to be done to find the optimum distances a cow should move between these areas. Some observation indicates that a crossover lane from the resting to the feeding area should be provided every 60'-80', or a row of 15-20 freestalls. Each crossover should contain a waterer and be wide enough, say 10'-12'. so that cows using the waterer do not block the lane. Floor And Traffic Lane Sur-

faces All surfaces that cows

come in contact with should provide a confident, non- skid footing. A floor surface

enough to walk in bare feet, it IS probably acceptable for dairy cows (Graves, 1993).

In high traffic areas where cows may be moving and/or turning in groups, a surface with good trac- tion is essential. In the milking parlor the floor surface is usually wet and must be easily cleaned. An anti-slip grit such as aluminum oxide can be trow- eled into the concrete after floating (Welchert, 1992). Installed properly, these surfaces provide an excellent non-skid surface which is easy to clean and durable. However, due to the abrasive nature of the grit, there is some concern about the amount of wear it may cause to the hoof if the cow is exposed to this floor surface continuously.

Separation, Isolation And Restraint Individual cows must periodically be separated

from the group for breeding, treatment, or special observation. A single handler should be able to isolate and restrain a cow with relative ease. Much of this process is based on animal behavior. Therefore, the handler should be familiar with the best and easiest methods for encouraging cows to move. Head- locks in the housing area and sorting lanes in the milking center can make this task much simpler.

Cows may be separated from the group easily as they exit the milking parlor. Cows are usually in single file in the return lane and can be sorted using a power operated cutting gate. The cutting gate may be controlled manually from the operator's pit in the milking parlor, or automatically by a transponder and identification arch. Catch lanes typically run parallel to the return lanes and can hold several cows briefly for observation. A headgate at the end of the lane provides simple restraint. Proper design of gating and pass-throughs in the catch lane allow the operator complete and convenient access to the restrained animal. A room/office adjacent to this area for the storage of breeding supplies, veterinary care products and instruments, and records is highly recommended. Hot and cold running water should also be available nearby.

A hospital/treatment area is necessary for cows requiring more rigorous examination, or longer term treatment or observation. This area should be sep-

arate from the housing area and milking center. The hospital/treatment area should provide the space and apparatus necessary to restrain a cow properly for examination and treatment, elevating and sus- pending feet, lifting downed cows, and surgery.

At least one treatment pen should be provided for every 50 cows (Graves, 1983). Each pen should be a minimum of 12'x12' (1 6'x 1 6' preferred) and allow simple animal restraint and support, convenient access (for both handler and cow), easy clean out and downed animal removal, access to feed and water, and contain a non-skid floor.

Animals are transported regularly. An area designed to accept and isolate animals coming into the herd and load animals leaving the herd is desirable. A loading chute or dock of convenient height for the truck(s) used should be provided (Graves and Light, 1980). A durable, non-skid surface is necessary in the loading area.

Ganglock, or self-locking, stanchions are commonly found along the feed manger in many dairy enterprises using fenceline feeding. Some stanchion designs allow one, several, or all of the group to be restrained briefly for routine examinations, such as pregnancy checks and treatment.

In housing arrangements using two rows of freestalls parallel to the feeding area, it is common to have more feed barrier openings than freestalls. This allows the entire group, even with slight overstock- ing, to be restrained at the fenceline at one time. In housing systems using three rows of freestalls parallel to the feeding area, there are approximately 25% more freestalls than feed barrier openings. Therefore, the entire group may not be restrained at one time, which complicates animal handling during routine examinations.

Access And Observation Proper design allows each group to be observed

easily and completely. Access to each group should be convenient. A person should not have to open a gate to enter any group. Convenient access to a group also allows escape if necessary.

Pass-throughs are commonly placed at each end, and in the middle of, each fenceline along the feed

delivery alley. They are also often placed next to gates used for cow traffic. Some gate designs incorporate a pass-though within the gate. The clear opening of pass-throughs range from 10”-16” depending on the location and person(s) using them. A rule of thumb is to use a 10”-12” opening where cows may face the pass-through, and a 12”-16” clear opening where cows ‘pass’ the opening. Self- closing, one-way gates should be used in pass- throughs wider than 16”.

Some dairy producers use decks strategically placed above groups for observation. The herdsman observes the herd for heat detection and general health from this location.

Freestall barns with fenceline feeding offer the opportunity for the herdsman or manager to drive along the feed delivery alley frequently to observe the herd.

Provide adequate access for a tractor, or skid- loader, to easily enter each group for the removal of

a downed animal. Freestall partitions should be designed for easy removal to f ree an entrapped cow.

Lighting Lighting in the housing area should allow 24-hour

operation and observation (Graves and Light, 1980). The minimum light available at any time should be 200 lux (20 fc) in the feeding area and 100 lux (1 0 fc) in the general housing area. In areas where close examination or surgery is performed, 1,000 lux (100 fc) is recommended (ASAE, 1992). Fixtures should be placed to minimize shadows and bright spots since animals lend to balk in these areas (Grandin, 1989).

Natural Ventilation Good ventilation is essential for good animal

health. Just by respiration, dairy cows produce three to five gallons of moisture per day. Good ventilation provides the air exchange necessary to remove this moisture, as well as other moisture, gases, heat and dust in the housing area. In most climates, natural

ventilation is the most practical system for freestall A continuous ridge opening is recommended. housing. Typically, 2”-3” ridge width should be provided for

Dairy housing structures should provideshade in every 10’ of building width. An open ridge is pre- the summer and block winds during cooler months. ferred, but gutters and ridge caps are sometimes Proper building orientation is important. In most used to reduce the amount of rain and snow which cases the ridge should be oriented perpendicular to enters the building. Generally, a ridge cap design is prevailing winds. This allows summer breezes to acceptable if it does not restrict the opening. blow across the width of the building when the side- Freestall (resting) Area walls are open, and the ridge opening to ‘draw‘ air Properly designed freestalls provide a clean, dry, more uniformly year-round. comfortable resting area with good air circulation,

Open-front buildings, especially those with a protection from other animals, and do not cause in- monoslope roof, should be oriented to provide shad- jury or trap a cow. Ease of maintenance is also im- ing during theafternoon in theafternoon. The build- portant, but animal comfort and cleanliness should ing should be located a minimum of 50’ from ob- be the primary concerns when selecting a freestall structions which might block air flow. The ’wind combination. shadow‘ created by tall and/or long obstructions The dimensions of the freestall should be allow may increase the necessary separation distance. adequate space to enter and exit the stall easily, and

Sidewalls should be 12’-14‘ high. This height rest comfortably. A cow rising in a natural way, such increases the volume of air within the housing area as in pasture, lunges forward, shifting her weight for- which can improve air quality. The intensity of heat ward allowing her hindquarters to be raised more radiation from the root material is also minimized easily. Observations indicate that cows prefer to improving hot weather comfort. The sidewall should lunge forward, rather than to the side, given the op- be open a minimum of 50%. However, 75%-100% . portunity. Cows can exit a freestall successfully and is preferred. When the sidewall is fully open, fresh without injury, when lunging to the side, but seem air should be introduced at the cow’s nose level more tentative and careful about their movements. when she is resting in the stalls. Recommended freestall length for Holsteins is

7’6” for stalls with open fronts, and 8‘0 for stalls with solid or slatted front barriers. For Holsteins (up to 1,600 Ibs.) stall width of 4 ’ 0 is adequate for animal comfort and minimum chance of injury while the cow is entering, resting in, and exiting the stall.

Stall partition height and design are also very important for cow positioning and prevention of injury. In stalls of

proper length, a brisket board and adequate stall base slope help position a the cow in the stall and keep the back of the stall cleaner.

The stall bed should provide good 'cushion' for the occupant. Cushion might be defined as a surface which gives slightly to cradle the bony protru- sions of a resting cow, distributing her weight more evenly across the stall bed. A comfortable stall bed will encouragethecows to use thestalls ratherthan the alleyways.

There are several stall bed alternatives which give adequate cushion. A earth stall bed with a generous bedding layer, and a clean sand stall bed are excellent choices, but should be maintained regularly to encourage cow acceptance, cleanliness, and prevent injuries. Embedding tires into earth or concrete makes a very stable stall base. The tire sections provide a degree of cushion, however, a generous bedding layer is still required.

Many producers have adopted fabric-covered freestall beds in their systems. This option requires less bedding since most of the bedding layer is contained beneath a layer fabric. After a firmly tamped base is established, a generous layer of bedding is added to the stall base. Next, a layer of heavy fabric, such as woven polyester, is placed over the bedding layer and fastened to the brisket board. With organic bedding such as sawdust, straw, shav- ings, hay and peanut hulls, the fabric may be draped over the rear curb. This allows easier access to the contained bedding layer to remove wet spots, level the bedding, or add additional material. A light layer of bedding on top of the fabric is still required to absorb ma-

nure and moisture tracked in from the alleys. More recently, shredded or chopped rubber has

become a popular choice as the contained bedding layer in fabric-covered stall beds. The rubber material is resilient and provides excellent cushion if installed properly. Observation indicates that 250- 300 Ibs. of shredded rubber is required per stall. The fabric is typically fastened at both the front and the rear of the stall to prevent the material from getting into the manure system.

'Freestall' does not mean 'free of maintenance'. The stalls need to be maintained regularly to insure cow cleanliness and acceptance. Manure and wet spots should be removed one or more times per day. The stall bed should be filled and leveled as required. Cows are reluctant to use, and may become trapped in, stall beds which are hollowed out or slope toward the front of the stall.

Feeding Traffic And Delivery One of the most important materials handling

tasks on the farm is the mixing and delivery of the feed ration. The design of the feeding system should provide the following:

1). Simple, convenient delivery of the feed to each group. 2). An area which encourages, and allows, each cow the opportunity to consume the proper amount of the ration. 3). Easy removal of old feed and debris from the bunk or feed manger.

General Layout And Considerations Fenceline feeding with a mobile mixer/feeder

allows flexibility in the location of feed storage and delivery location. Several rations may be mixed and delivered to different groups, buildings and/or other farms using the same equipment. If only a one-feed mixing and delivery vehicle is used, a trailer- mounted model is preferred over a truck-rnounted model since an alternative power unit (tractor) may be connected if the regular unit is down.

Forage storage should have convenient access from fields. Supplement and/or commodity storage(s) should have convenient access from the high- way. (Brugger, 1990).

Brugger (1 990) suggests that the layout of the storage, mixing and feeding areas should be designed around a good traffic pattern. All sites, and the roads between, should be well drained and able to support daily traffic year-round and in all types of weather. The feed delivery unit should move forward with a minimum of backing. Adequate space and reference markers should be provided when the delivery unit must be backed into place.

Wherever animal traffic lanes cross the feed delivery units regular path, cattle guards and automatic gate and door openers allow the feeding unit to pass through without requiring the operator to leave the controls.

The width of feed delivery alleys range in width from 6'-20'. The size and type of equipment used is typically the determining factor. The mobile feed delivery unit should be able to pass through the feeding area without running over feed on the opposite side or endangering animals feeding at the fenceline.

The recommended feed delivery alley width for a drive-through freestall arrangement is 18'-20'. Each feed manger requires 30"-36" for feed delivery. This leaves 12'-15' for vehicle traffic.

The doors to the feed delivery area should provide a clear opening from manger wall to manger wall. This allows easier maneuvering of the feed delivery unit. Also, old feed may be mechanically pushed or swept from the building more easily.

The height of the feed delivery alley doorway should allow the tallest piece of feeding equipment to enter. Door heights of 10'-14' are commonly found. The recommended height is 14' or more.

For drive-by feeding, typically used with open front building layouts, the feed delivery alley may be narrower. However, the mobile feeding unit should run on a well drained, durable all-weather surface.

Feeding Space The amount of feeding space allowed varies with

the type of ration delivered, amount of time the group spends away from the feeding area, frequency of feeding, and personal preference of the dairy pro-

ducer. If the entire group is to be fed at once, 28”-30”

of feeding space should be provided for each cow in the group (Bickert, 1990). A freestall housing arrangement using two rows of freestalls parallel to the feed manger and properly sized cross over lanes can provide feeding space within this range.

The longer that cows are kept away from the feeding area, or that feed is not available to them, it becomes more important to provide enough feeding space to accommodate the entire group at once. If forages are fed and then top-dressed, space should be provided to give the entire group the opportunity to consume the ration. Some producers who have switched from two to three milkings per day have noticed that more of the group uses the feeding area at the same time. This seems especially true when group size exceeds the number of cows which can be milked in one hour.

I f a total mixed ration is fed and readily available

to the group, 18”-24” feeding space is adequate (Speicher et al., 1982). However, Bickert (1 990) points out that as barns are designed and built to milk cows in the future and higher milk yields are anticipated that stress animals further, the advisa- bility of reduced feeding space must be reexamined.

The Feed Manger Eating surfaces must be smooth, clean and free

from left over feed and other debris in order to encourage good feed intake and aid in the control of disease (Bickert, 1990). The low pH of silage can etch the manger surface, exposing the cow‘s tongue and mouth to rough edges (Albright, 1983). High- strength concrete and admixtures are often used to improve the durability of feeding surfaces where silages are fed. A 24”-30” ribbon of tile along the length of the feed manger will provide a durable, smooth surface if installed properly. Epoxy type coat- ings may also provide adequate resistance, but must be applied properly to allow good adhesion.

A manger height which allows cows to eat in a natural grazing like position is preferred. Feed toss- ing is also reduced in fenceline feeding with manger elevations at or near floor level, compared to deep bunks (Albright, 1983). Manger surfaces elevated 2”-6” above the cow alley work well. Minimizing thiselevation maximizes the manger wall which the ration can be piled against. The recommended throat height for the manger wall, measured from the cow alley, is 21“ (Bickert, 1990).

A flat feed manger surface on the same level as the feed delivery alley is preferred. This allows the manger to be easily cleaned mechanically or by hand. It also allows the opportunity for good air circulation in the feeding area. The feed manger should slope slightly away from the fenceline, approximately 1/8” per foot to help drain away unwanted moisture.

Feed will be pushed out of reach by the cows and must be swept-pushed back regularly. This can be done by hand or mechanically. Several dairy producers have recognized this task as necessary and useful in the observation of the cow groups.

The Feed Barrier The feed barrier is a divider which separates the

animal area from the feed manger. The feed barrier should provide convenient access to feed, yet confine cows to their group. It can also reduce feed waste.

The post and rail barrier is typically made of metal or wood vertical posts which support a horizontal neck rail. The neck rail may be made from pipe, cable or plank. This alternative is inexpensive and allows excellent access to feed. A typical installa- tion of a post and rail feed barrier is shown in Fig- ure 6. In cases where competition for feed is a concern, such as with limited top-dressed feeding, a feed barrier which divides the animals may be preferred (Bickert, 1990).

Tilting the top of a divided barrier forward 4”-6” helps reduce pressure on the shoulders of a feeding cow. It also allows her to reach further for feed. A stanchion design which allows the neck opening to be opened wider at the bottom to quickly release a

downed cow IS preferred. Water Stations

The availability of a continuous supply of clean, fresh water is essential for lactating cows. More research is needed to determine the location and type of waterers which should be used. In the meantime, make drinking water plentiful and convenient throughout the housing area, especially during hot weather.

The minimum design guidelines are to provide one waterer location or 2’ of tank perimeter for every 15-20 cows in a group (Bickert, 1990). Just as important, the waterers should be conveniently located to allow cows easy access. A water station should be located in each crossover area between the feeding and resting area. Many producers have also found their cows frequently use water stations located along side traffic lanes as they return from the milking center.

Each waterer should be easy to clean and cleaned regularly. Tilting water tanks allow easy cleaning of the tank and the flush of discarded water can be used to clean cross over areas. Water tanks and vats should have drain plugs near the bottom to allow complete removal of water and debris.

Manure Collection And Transfer The least favorite task on most dairy enterprises

is often the collection, removal and distribution of animal waste. Regular and efficient removal of waste from the housing area is essential to provide more sanitary conditions and cleaner cows. With proper planning and design, manure removal can be sim- plified to allow effective cleaning with a minimum amount of labor.

General layout And Considerations To facilitate cleaning, cow alleys should be

straight with no turns or dead ends. Moving manure around corners isdifficult, time consuming and frus- trating. Each side of the cow alleys should have a curb to contain manure and urine within the alley during collection, allowing more efficient waste removal. These curbs should extend to the collection opening. The rear curb of the freestall rows

should be high enough to prevent manure from overflowing into the stalls during removal. At crossover lanes, curb height should not be more than 8". The crossover lane should be crowned slightly to drain moisture into the cow alleys. Cow alleys should be level across the width. An

uneven alley floor results in incomplete cleaning and allows liquid to puddle.

A manure collection opening should be located at the one end of each cow alley. The alley should slope at least 1 %, but not exceed 5%, toward the collection opening to give liquids the opportunity to drain. The collection gutter or pit should be at least large enough to accept the amount manure from all of the alleys it services. Tractor-scraped alleys require more collection capacity than mechanically scraped alleys, since the alleys are typically scraped less frequently and more rapidly.

The collection opening should beat least 1 2" and span the entire width of the alley. The opening should be covered or guarded from animal and people traffic. The opening should not interfere with cow, or vehicle, traffic. Grates are often used to cover collection openings to allow manure to pass through and cow traffic cross. However, a grate with an acceptable opening for cows traffic, say 1 ", does not allow manure to pass through easily.

A good location for the collection opening is just outside the traffic lane fence. The opening can be fenced to prevent accidental entry, yet remain open to allow manure to be scraped to it without lifting a cover or opening a gate. If the building arrangement allows manure collection between groups a section of the building, say 2' in length and the width of the building, can dedicated to the collection of scraped manure. This area can also cover a gravity-flow gutter to transfer waste from the building.

Collection methods: The most common methods of removing manure

from the cow alleys of freestall barns are tractor scraping, mechanical scraping, flushing, and slatted flooring.

One common method of cleaning alleys in freestall housing is with a tractor-mounted scraper blade

or skid-steer and bucket. This can be a very economical and flexible alternative since one piece of equipment can be used in several locations, and also be used for other tasks. The preferred time for alley cleaning is when the cow group is away from the area to reduce stress, excitement and chance of injury.

Metal scraper blades can smooth floor surfaces, making them slippery and hazardous for cows to walk on. For several years, largequartered tires (split lengthwise, then in half) have been used as a scraper blade alternative. 'Tire scrapers' do not wear the floor surface smooth and do an excellent job of cleaning.

Mechanical scrapers are pulled by a chain or cable. They move slowly in the alley allowing cows to step over them when they pass. Mechanical scrapers can be controlled to automatically cycle several times per day, or run continuously if desired. The main advantage is thatthealleyscan becleaned frequently with cows in the housing area and without human labor. However, hand cleaning is still required at cross alleys and at the end of the alley where the scraper blade cannot reach.

Slatted flooring has gained popularity with some dairy producers. Openings in the floor allow manure and urine to pass to a collection gutter or storage below. Manure is worked through the openings by the feet of the cows during normal traffic. The result is, typically, alleys that are very clean and dry which may contribute to good foot and leg health.

There does not seem to be a consensus among dairy producers, animal scientists, veterinarians, builders, or agricultural engineers on the use of slatted flooring in lactating cow housing. It seems that this too is a topic that needs more controlled study. Some of the pros and cons seen by those who like and dislike slatted flooring are listed below:

Advantages of slatted flooring: 1). Provides excellent dry floor surface for cows. 2). Don't need to enter cow group to clean alleys. 3). Non-mechanical manure collection. 4). Cows tend to stay cleaner, even if they lay in alleys.

5). Less manure tracked into freestalls. 6). Manure storage under building (saves space and

pumps, and an irrigation system. Careful thought should be given to how both the solid and liquid portion of the waste will be managed.

Alley Cleaning Frequency The cleanliness of cows is directly related to the

frequency which the alleys are cleaned. Producers have noticed a considerable increase in cow cleanliness when scraping frequency was increased from two times per day (approximately 1 2 hrs. apart) IO

three times per day (approximately 8 hrs. apart). Mechanical scrapers can be operated continuously or programmed to scrape at selected intervals throughout the day. More frequent scraping allows less manure to collect in the alleys and can provide a better environment for cow cleanliness and foot health.

Hand cleaning of some areas is difficult to avoid. Cross alleys, freestalls, and areas out of reach of the scraper must be cleaned regularly. The secret is to make this task simple and convenient so that it will get done. Place the necessary tools, such as scrapers and brooms, near the required areas. They should be out of reach of the animals and not interfere with animal or feeding traffic.

Summary Housing designs that keep cow comfort in mind

provide the opportunity for good feed intake, milk production and herd health. Proper planning can also make the tasks of feeding, animal handling, milking and waste collection more convenient. When the housing design combines animal comfort and effective use of labor, more time can be spent on management of the dairy enterprise - which often leads to improved profitability.

out of sight).

Dlsadvantages of slatted flooring: 1). Cows hesitant to walk on slatted flooring. 2). Manure builds up on slats making them hard for

3). Manure storage under building (gases and odors). 4). Cows may injure their feet and legs in the open-

5). Expensive.

‘Conventional’ slats use a 1.75”-2” opening between treads approximately 6”-8” wide. The opening spans the width of the cow alley. A design becoming popular in some areas is the ’waffle‘ slat. This design uses a series of openings approximately 1.75”x8” spaced about 3” lengthwise and 5”-6” apart. In use, cows seem to walk very comfortably on this flooring surface and manure passes through quite easily.

The best advice to give producers considering slatted flooring is to go see several installations where it has been used by dairy cows for a few years or more. The combination of the owner and manager comments, and personal observations should be helpful in making a final decision.

Flush systems have been used in warm climates to clean alleys for many years. They have become more popular with new dairy systems in the North- east and Upper Midwest. Properly designed and managed, a flush system can provide efficient and complete cleaning of the cow alleys. Flushing will not wear the floor surface and cleaning may be done while the cows are in the housing area. If temperatures are too cold to flush the alleys, they can be cleaned with a tractor and scraper easily since there are no obstructions in the alleys.

Flush cleaning IS a system that needs to be designed and managed properly. It uses a tremendous amount of water, even if it is recycled. A flush system includes flush tanks or valves, a collection pit, a separator, settling basins, water storage tanks,

cows to walk on.

ings (although few users complain of this).

References: 1. Albright, J.L. 1983. Putting together the facil-

ity, the workerand the cow. Proceedings of the Sec- ond National Dairy Housing Conference, American Society of Agricultural Engineering SP 4-83, pp 15- 22.

2. Armstrong, D. V. 1993. Personal communication. Extension Dairy Specialist and Research Sci- entist, University of Arizona, Tucson, Arizona.

3. ASAE. 1992. Lighting for dairy farms and the poultry industry. ASAE Standards, EP344.2. pp.473- 476.

4. Bickert, W. G. 1990. Feed manger and barrier design. Dairy Feeding Systems, Proceedings from the Dairy Feeding Systems Symposium, Northeast Regional Agricultural Engineering Service, NRAES- 38, p p 199-206.

5. Brugger, M.F. 1990. Mobile mixer systems for total mixed rations. Dairy Feeding Systems, Pro- ceedings from the Dairy Feeding Systems Sympo- sium, Northeast Regional Agricultural Engineering Service, NRAES-38, p p 149- 154.

6. Grandin, T. 1989. Behavioral principles of livestock handling. The Professional Animal Scientist, American Registry of Professional Animal Scientists, Volume 5, Number 2, December, pp. 1 - 11.

7. Graves. R. E. and R. G. Light. 1980. Animal handling and movement. Milking Center Design Man- ual, Proceedings from the National Milking Center Design Conference, Northeast Regional Agricultural Engineering Service, NRAES- 12, p p 242-252.

8. Graves, R. E. 1983. Restraint and Handling Sys- tems for Dairy Cattle. Proceedings o f the Second National Dairy Housing Conference, American Society of Agricultural Engineering SP 4-83, p p 186- 194.

9. Graves, R.E. 1993. Personal communication. Professor of Agricultural and Biological Engineer- ing, The Pennsylvania State University, University

Park, Pennsylvania. 1 McFarland, D.F., 1994. Designing dairy hous-

ing for convenient animal handling, feed delivery, and manure collection. Dairy Housing for the 2 1 st Century. Proceedings of the Third International Dairy Housing Conference. American Society of Agricultural Engineers. pp.503-5 14.

11. McFarland, D.F. and M.J. Gamroth, 1994. Freestall design with cow comfort in mind. Dairy Housing for the 2 1 st Century. Proceedings of the Third International Dairy Housing Conference. American Society Of AgriculturaI Engineers. pp. 159- 164.

12. McFarland, D.F. 1992. Designing for operator comfort and convenience. Milking Center Design Manual, Proceedings from the National Milking Center Design Conference, Northeast Regional Agricultural Engineering Service, NRAES- 66, p p 230-247.

1 Speicher, JA.. W.G. Bickert and M.S. Stephenson. 1982. Effect of feed bunk space on milk production. American Society of Agricultural Engi- neers Paper No. 82-4005, St. Joseph, Michigan.

14. Welchert, W I 1992. Personal communication. Agricultural Engineer, Tucson, Arizona.

15. Welchert, W. I 1992. Anti-slip concrete floor specifications. Milking Center Design Manual, Pro- ceedings from the National Milking Center Design Conference, Northeast Regional Agricultural Engi- neering Service, NRAES-66, p p 200-203.

Dairying In The Future:

and coming challenges. Some questions you may want to ask about past experiences

ne could design an entire conference . around the subject of what dairymen will The overall size of the dairy sector is dependent 0 need to know to dairy in the 21 st century upon sales, and sales are determined by the chang-

and beyond. Most of the answers can be found In ing demands and desires of consumers and their reviewing the past. I have chosen to zero in on just willingness to spend hard dollars on what they per- a few areas I think will k Important for dairymen ceive to be the healthfulness of the foods they eat. to consider as our industry progresses into the next Change will continue to be the common denom- century. Let’s not dwell too much on where we are inator in the dairy industry. In the mid-1 940s, 5 mil- today, because dairymen who are not on the cut- lion farms reported milk COWS. By 1959 well under ting edge and using the tools available to them prob- 2 million farms reported milk COWS. Reductions in

advances.

ably will not be around to be competitive in the years to come. Ours is a shrinking industry when it comes to numbers of people involved, yet truly a growth industry when it comes to production per cow, output per man hour and rapid technological

farms with dairy cows dropped even more percentage wise during the 1960s, when dairy operations terminated on more than 1.2 million farms, a 10- year decrease of 68%. This trend has persisted in the 1970s and 1980s. The 1987 census reported

202,000 farms with milk cows. In 1987, two-thirds or 138,000 dairy farms, accounted for over 90% of all milk cows in the U.S. This reduction in dairy farms has been accompanied by rapid declines in the size of the nation’s dairy herd. During the 1940s and early ‘50s milk cow numbers were nearing the 25 million number. Major decreases brought cow numbers near 11 million in the mid 1970s. By 1993, the number of milk cows dropped below 9.8 million - the smallest national herd in over 100 years.

The decrease in milk cow numbers is a result of farm productivity increasing at a faster rate than dairy product sales. A look at productivity trends

shows a steady increase in milk per cow. US. dairymen have realized a 300% increase in average milk production since 1940, from 4,600 Ibs. per cow to about 15,500 Ibs. per cow in 1993. Since 1960 the rate of gain has been about 275 Ibs.per year. I look for this trend to accelerate substantially.

Census data shows the average herd size going from 5 cows in the 1940s to just over 50 cows in 1987. Data for 1993 indicates that there were 9.7 million cows on 175,000 farms. Production per cow average 15,554 Ibs. and commercial disappearance of products was 150 billion Ibs. of milk. Assuming milk production only keeps up with population

growth of about 1 % per year and production per cow grows at its historic rate of about 2% per year, then cow numbers must decline over 10% by the year 2000. If farm size moved up from 55 cows to an average of 75 cows per dairy, the number of dairies in the U.S. would decline about 35%. One can surmise from the above if new technology increased production to 3% from the historic 2%, then cow numbers would decrease by almost 19%

by the year 2000, all

else being equal. If we assume technology advances results in more larger farms and greater productivity gains to the point that the average herd size rises to 100 cows instead of 75, then farm numbers will decline 51 % over the next 10 years.

By the year 2000, there will be 8.5 million cows in the US. on about 90,000 dairies, with production of about 18,500 Ibs. of milk per cow totalling 157 billion Ibs. of milk. The greatest production increase will be in the West. New York and Pennsyl- vania will show moderate growth and by the late

1990s production in the upper Midwest may rebound.

One of the areas I want to look at and talk about is one we don‘t pay enough attention to in the dairy business: the socio-economic area. Recently, the Roper Group conducted a survey in rural areas. The questionnaire asked, “What do you need for your family to make a comfortable living, to set aside money for a college education for your chil- dren, retirement” and so on. The answers were gathered geo- graphically with those surveyed in the Northeast responding

$40,000, the South $30,000, the Midwest $30,000 and the West $40,600.

Now if you relate these answers to dairy fam- ilies and assume the average dairy producer in the U.S. produces about 1 million Ibs. of milk a year; in order to have the lifestyle the survey indicates he'll feel comfortable with, one needs to net $3 per cwt. That's not happening; nor is it likely to happen. I wanted to start with this premiseand show why it will take an extremely competitive, efficient producer to meet the income goals referred to in the Roper survey.

Recently, Ed Fiez and Dean Falk, with the Uni- versity of Idaho Extension Service, studied milk production costs and returns; their conclusions are significant. They found at the 18,000-lbs. milk level one can expect $1 79 in return to labor, management and risk. But as milk production level increases to 20.000 Ibs., or roughly 10% more, the return for labor and management didn't go up 1 0% ... It went up 100%. As we look at the 22,000-lbs. levels, we see a tremendous increase in return for labor, management and risk. Almost three times the original return. Re- membering the survey results: If the dairyman is currently shipping 1 million Ibs. of milk a year and trying to net $35,000, the only practical way for him to do it is to increase production to 22,000-lbs. or more and/or increase herd size.

Now if we look at the U.S. averages for production in Figure 4, we're only two-thirds of the way there, so we've got a lot of producers who are not on the competitive edge. Their future as dairymen and providers of income at the comfort level is in jeopardy.

In a study done a few years back, the Stanford Research Institute projected total costs of production in different geographic areas out to the year 2000. In 1987 costs varied from a high $1 2.70 in the Southeast to a low of $1 0.42 in the Pacific region, or a $2.28 per cwt. spread between top and bottom. In 1988, even though the total costs rose in all areas, the variance from the average ranged from a high of +$1.32 to a low

of -$1.99. When we project out to the year 2000, we see a greater total variance of $3.85 than we saw during earlier years. In all cases the Pacific states had a tremendous advantage in costs of production. The Pacific region and the Southwest have many cost advantages in common. There is no doubt these areas will continue to grow and lead the rest of the nation by a wide margin in growth. The Northeast shows promise as a dairy area of growth and one that will be able to compete. How- ever, the historic area for milk (or residual milk supply for the United States) is beginning to shrink. The SRI study done in 1986 predicted this would occur and the events since then have shown this to be the case. A significant "retooling" will be necessary before this region rebounds.

If we remember chart 4 showing the top five states in the country (all in the West) averaged 19,000 Ibs. of milk and the bottom five states( mainly in the Southern region) with average production of 11,500 Ibs., we can get a pretty good sense of who is going to be competitive and who is not. Individuals operating at these lower levels are not going to be able to stay competitive with

those on the other end of the spectrum. This becomes even more important as we become players in the world dairy markets. If we are looking at 8,000 pound differences between averages in production levels in herds that range let's say from 200-400 cows, we are looking at competitive disadvantages you cannot compensate for by cheaper costs of land, labor and other inputs.

I would like to spend some time reviewing data I analyzed from the California Department of Food and Agriculture Milk Stabilization Branch. In Califor- nia about 20% of all the herds are on state-audited cost of pro-

duction studies. The herds are selected at random and about 15% of the herds are turned over annu- ally. The cost data is collected by field auditors who actually spend time at the dairy collecting the data which is later analyzed, summarized and used in the formula for setting the state’s Class 1 price. While the state personnel use these numbers in pricing, many of us use the data for many other purposes including production trends, competitiveness of our members, and so on.

Without question the single most important factor in determining profitability per herd is the level of production. The two major production areas of the state are the North Valley and the South Valley. A review of herds ranked by production level clearly shows a very strong dollar advantage in those herds with higher production. The advantage is in the form of net receipts per cow, net income per cow, and net income per hundredweight. One can argue for

lower costs and other efficiencies, but level of production in general is the most important factor in profilability.

While herd size appears to give some indication of profitability it appears that once the area of dimin- ishing returns is reached net income when measured by cow or by hundredweight is quickly erased. My guess is management loses the ability to keep the operation "fine tuned" and slippage occurs in the

area of feed efficiency and other costs. Having looked at regional costs domestically, I

would like to turn our focus on world markets; after all, that's what both the NAFTA and GATT agreements were all about. Like it or not we are stepping beyond competing with each other for the U.S. market and looking at international markets. That's what DEEP, DEIP, NAFTA and GATT are all about.

Before looking at world demographics, I want to take a moment and compare U.S. dairy trends with some interesting trends in the European community. The EC-10 has had a very rigid supply management program beginning in 1985. Since 1978 when the EC-10 dairy herd numbered 25 million, it is now below 19 million - a six million cow reduction while, during the same time, the U.S. herd decreased by roughly 1 million head. The EC-1 0's rate of reduction was about 2.5 times the U.S. rate.

An even more interesting trend to look at is per cow production. The difference between the U.S. and the EC- 10 was about 2,200 Ibs. per cow, or 78% of the U.S. level. In 1992, the dif-

ference increased to 4,400 Ibs. per cow. In other words, EC-10 yield had dropped to 72% of U.S. yield.

How much of loss of productivity was due to the quota system? If this trend continues won't the European Commu- nity become even more uncompetitive? With- out increased subsidies or a renewed interest in regaining it's lost rate of productivity, the EC-10 may be over run with

imports from less expensive products produced more efficiently elsewhere.

In one of the publications that John Naisbitt has written, "Mega-trends 2000”, he predicts a number of things are going to occur over the next few years. For the rest of the 1990s and into the year 2000, he predicts a booming global economy and that North America, Europe and Japan will actually form a great triangleof FreeTrade. (This was written before GATT, NAFTA or DEIP.) If this is going to occur, dairying will need to become part of the big picture. He says we will soon learn to forget about the term "trade deficit" between the U.S. and Japan. His example is, can anyone tell us what the trade deficit is between Rochester and Syracuse, Seattle and San Fran- cisco or Denver and Dallas?

He calls for an emergence of free market social- ism. Basically, protectionism as such is dying, and

it is dying very quickly. As the globe becomes smaller and smaller you learn and need to be competitive. Naisbitt talks about the rise of the Pacific Rim. Its population is more than twice that of the U.S. and Europe combined. He says Los Angeles, Sydney and Tokyo will replace New York, London and Paris as the cities of World Trade and World Importance in the years to come. He talks about the late 1990s becoming the 'Age of Biology' in the world economy. (Maybe biotechnology is more accurate.)

In looking at the numbers we can see the tremendous potential in Asia for dairy products. While that part of the world has 56% of the population, it only produces 9.3% of the world's milk.

Let's see how we stack up using cost of production numbers. Even though the data in Figure 11 is somewhat dated, I believe the relationship between

costs is still pretty much in line. As you can see, the U.S. and especially the Pacific states can compete very well internationally. Even though New Zealand has by far the cheapest costs in the world, its total production is about equal to California’s and it is questionable just how much more “cheap” production growth is available there.

If we examine our competitiveness based on farm milk prices we get an even better perspective about what our relative position is with competing nations for dairy sales. If GAlT truly does moderate the level of farm subsidies, we should be nicely positioned to sell dairy products in a number of markets.

We can see some of the markets that could be real boons for our dairy producers in the near term. In fact, Mexico has been a real bright spot for U.S. dairy products since 1990. Even though the DElP program helped make us competitive in this market, the per capita income growth in Mexico is creating a whole new generation of buyers with money to spend. Currently, per capita consumption is about one-third that of the U.S. With over 90 million con-

sumers, Mexico should remain an excellent growing market for years to come.

The National Dairy Board recently published some data showing projected demand in Southeast Asia for the 1990-1 996 period. Their numbers indicated a 45% growth. in dairy imports.

As these growth trends continue to develop in international markets, it becomes increasingly evident that only those producers who are committed to increasing production levels and efficiency levels will be in a position to compete for the market- place. The marketplaceas we have known it is being redefined with a new global perspective. Those producers who expect to be players in the next century will have to be innovators. Their abilities to manage will have to be keen. They must be able to adopt new technologies and adapt to changing markets. They will have to be in the upper end of the management scale. High production per cow; low costs per pound of milk produced. They will have to make things happen.

Economic Decision Support

Systems For Dairies

airy managers need to make decisions. nomic information using forecasting and optimiza- Some decisions affect farm and business tion techniques. taking dairymen beyond produc- D structure and thus have long term conse- tion summaries toward useful economic decision-

quences. These strategic decisions have effects over making tools- a number of years, affect the fix cost structure of the The dairy business is composed of at least two business, and are based on long term planning. Tac- inseparably liked components. a Production entity tical decisions are intermediate in term, with con- and a financial entity. Traditionally, planning and sequences over a year and are made within the con- management systems have been developed sepa- text set by the long term strategic plans. Day-to-day rarely within these two entities with little functional operational decisions reflect the implementation of (causal) connection between them. Comparative specific production practices within the framework analysis commonly searches for relationships be- of the tactical plans. Information is needed to sup- tween production characteristics and financial mea- port these decision activities and must aid in the sures. but this yields little more than correlations. translation of strategic financial plans into specific However, economic models must contain causal production practices. Farm level objectives need to components because managers are interested in the be translated into specific strategies within organi- economic consequences of production manage- zational areas such as production and finance. Mon- ment decisions. This functional link between pro- itoring performance and making needed adjust- duction and finance is largely missing in current ments in a continual process of control is an addi- information systems. except tor occasional sharing tional function of management. of database information. With the advent of micro-

Many dairies try to use production information computers and spreadsheets many "economic" such as DHI reports when making economic deci- analysis tools have appeared, but most have not sions, but few successfully link it with economic been scrutinized for economic validity or have information. I t seems obvious that decisions must ignored important factors such as interactions be based on economics, but this is difficult because between production activities on dairies and varia- it requires integrating production performance (milk tions In prices and costs. Most are formulated by production, dry matter intake, conception rate, in- animal scientists and simply assign costs and returns voluntary culling, etc,), environmental influences to a single production activity. Factors other than (seasonal climatic effects, nutrient recycling, etc.), production affect profitability. These include con- and financial information (expenses, revenues from straints and opportunities created by the physical outputs, capital investment, etc.). Data compiled for environment, prices received and prices paid, mar- financial reporting, including tax reporting, usually keting arrangements, size and volume of the busi- are designed for external interests, for example ness, labor efficiency, cost control, capital efficiency, lenders or the Internal Revenue Service. Although selection and combination of enterprises, and this information is often the only economic infor- choice of production practices within enterprises. mation available, many times i t is not immediately Planning, Control and Models useful for internal operations management of the Planning and controlling operatlons require infor- production activities on the dairy. Even if the proper mation for describing past performance, monitoring data are recorded and summarized in a historically on-going performance, forecasting tuture perfor- descriptive form, they are rarely processed into a mance, and choosing and taking appropriate actions predictive and prescriptive form useful to aggressive in a continual process of adjustment while seeking managers. Economic decision support systems for to achieve business goals. Information needs for management are needed. These systems should decision support depend on the extent to which integrate historical production records with eco- managers pursue these activities, and this informa-

analysis is generally well-developed in the dairy industry and has been an important tool for dairy extension activities.

Because of the disproportionate development and use of production recording systems compared to financial information tools, management decision making has often focused on production targets and norms. Production goals are clear, concrete and relatively easily defined, measured, and assumed to be an adequate proxy for more diificult economic goals. On the contrary, economic analysis demands the simultaneous consideration of input costs, output prices, input and output quantities, plus the functional relationship between inputs and outputs. In this way, for instance, the economics of pasture based systems can be correctly analyzed.

Besides providing descriptive and diagnostic information, useful management information systems must provide predictive information for planning, and prescriptive information (advice) for improvement. Prediction

and recommendations are important to determine whether and what intervention is necessary to try to alter the future. This information depends on causal, or functional models. This will be discussed later, but a complete system uses a combination of data gathering, data summarization, simulation, and optimization or searching methods to produce the information at the four levels of the hierarchy shown in Figure 1 . A key feature is that the production, economic, and financial models are totally integrated.

Accounting Information Accounting records are a foundation for eco-

nomic and financial planning. Some detail is appropriate in discussing accounting because of its importance to business success and the information systems being discussed. It is also the authors' experience suitable management accounting systems can be lacking on some dairies.

Accounting aids decision makers by matching corresponding output and input quantities with their prices and costs and summarizing this information

tion can be organized into a hierarchy reflecting the aggressiveness of management (Figure 1). The different kinds of information are generated from the interplay of data, data processing, norms and standards, quantitative models, rules, and optimization procedures.

Descriptive information provides the foundation to generate diagnostic, predictive, and prescriptive information needed for management action. Exam- ples include whether milk production is too low. dry matter intake is too low, feed costs are too high, net farm income or rate of return on assets are too low, or cash flow IS below budget. The immediate utility of existing descriptive information systems depends on whether the data are summarized on items that are under management's control and which can be compared directly with standards important for achieving important financial goals. Thus, descriptive information coupled with norms and standards, derived externally (comparative analyses with other dairies) or internally (management goals), provide the basis for diagnostic evaluation. This type of

to generate reports in formats which describe business performance. Accounting information serves three broad purposes:

1 ) . It provides routine information for cost management and controlling of production operations.

2). It provides special, or non-routine, information to managers for strategic and tactical decisions, capital investment, and formulation of overall policies and long-range plans.

3). It provides information through standardized financial statements and tax returns concerning the financial position of the business to external parties such as investors (e.g., lenders), government authorities (e.g., IRS), and others for financing, investing, and other decisions. Commission (SEC).

Unlike production records, accounting information necessarily serves many masters. In different instances the type of accounting information needed and its reporting format depends on whether the decision maker is internal (e.g., manager, owner) or external (e.g., investor, creditor). This duality in users leads to two main branches of accounting: management accounting and financial accounting. Tax accounting can arguably be considered as a third. The primary objective of financial accounting is an accurate representation of a firm's economic and financial transactions, while tax accounting follows what is called the 'least and latest' rule whereby the objective is to pay the least amount of taxes at the latest possible date within the law.

External Reporting. Reports generated by the financial and tax accounting systems include tax returns and schedules, and the principal financial statements: the balance sheet, the incomestatement, and the statement of cash flows. To maintain sources of capital inflow it is critical for dairy producers to provide investors and creditors with accurate information so they can assess the amount, timing, and uncertainty of cash flows to them. Cash flow prospects for investors and creditors are affected by the dairy's economic resources (assets) and the claims (liabilities) on these resources (balance sheet), the dairies financial performance (income statement), the dairy's sources and uses of cash (cash flow

statement), and the dairy's overall stewardship of resources (all three financial statements).

Because financial accounting is geared to producing information for decision makers external to the business, it is critical that the information be reported in a format recognized by all potential users of the information. In the United States the principal financial statements for public firms (publicly owned =selling stock) must be prepared to conform with generally accepted accounting principles (GAAP). These rules haveevolved overtimeor have been promulgated by official rule-making bodies such as the Financial Accounting Standards Board (FASB) as sanctioned by the Securities and Exchange

Agricultural firms generally fall outside of the domain of the FASB and the SEC. Therefore, much less uniformity exists among financial statements for firms in the agricultural sector. In some ways this can be a problem, because it makes comparing financial performance across farms more difficult for advisers and potential capital sources. Toovercome this problem the Farm Financial Standards Task Force (FFSTF) was formed in 1989 and published the Financial Guidelines for Agricultural Producers in 1991 (FFSTF, 1991 ). The intent of the FFSTF guidelines are to bring greater standardization to financial reporting and analysis for agricultural producers and to move agricultural financial reporting into closer conformation with GAAP while maintaining aspects unique to agriculture. It is always of interest to compare performance, yet this is only possible if there is uniformity in reporting. Selection or design of a system for recording, organizing and summarizing financial accounting information should conform to the FFSTF guidelines.

lntemal Reporting. Management accounting focuses on serving the first two functions of accounting information and is primarily aimed at the needs of internal decision makers. For this reason, complete standardization of management accounting systems across all dairy enterprises is probably an unrealistic and undesirable goal. Useful similarities can be expected, however.

In the dairy business the primary use of management accounting information is by managers for cost control. This type of accounting is sometimes called cost or enterprise accounting and is widely used and highly developed in most major corporations. How- ever, it has rarely been implemented in a consistent and systematic way by dairy producers. In the dairy industry, financial accounting has generally been the sole source of financial information, and because dairy financial accounting may be relegated to outside professionals whose primary role is preparation of the tax return, financial reports can be difficult for producers to use for cost control and analysis, especially at the tactical and operational level. Financial statements are usually highly aggregated; therefore, they are ill-suited for specific analyses such as determining the cost of specific production activities.

Well developed management accounting systems can provide the needed information because they are organized around items or activities for which separate measurements are useful. Figure 2 illus-

trates this in comparison to financial accounting. Management cost information may provide routine information necessary for culling and breeding decisions for individual cows or nonroutine information necessary for making longer range strategic decisions such as whether to raise or purchase replacements, or grow or purchase feed. On dairies typical cost items can span several levels of aggregation such as the cost of the entire milking herd, cost of individual cow lactations, cost per pound dry matter, or cost per hundredweight of milk. The same accounting information can have multiple uses depending on which decisions are required.

Thus, the system must have the capability to accumulate all cost data according to 'natural' dairy business classifications, such as feed, breeding, labor, etc. It must be possible to allocate, or trace, costs to individual items or activities. For example, a load of feed may be coded for the milking herd in general, for a specific group of cows, and for a speci- ficindividual cow(s). Direct costs can be traced easily, while indirect costs can not. For example it is

relatively easy to directly trace feed costs (a direct material) and milking labor (direct labor) costs to the milking herd. However, it is difficult, if not impossible, to directly trace costs like elec- tricity, insurance, property taxes and supervisory com- pensation to the milking herd, especially if the dairy consists of multiple enterprises (e.g., crop production, replacement rearing, etc.). Indirect costs, or overhead, can often be allocated using a formula.

Especially on large dairies, the proportion of total costs that are direct costs would be much higher for the milking herd than for individual

cows. For example, the veterinary and medicine expense for the entire milking herd would be rela- lively easy to directly trace. However, the true veterinary and medicine cost may be difficult to trace directly to individual cows.

Management information systems capable of providing dairy managers with reliable forecasts or profit maximizing strategies demand accurate and well-designed management accounting systems at their core. Cost control is critical. But additionally, it is difficult to choose between production alternatives without knowing the resulting costs, so costs must be known so that production decisions can be based on economic criteria.

Economics Economic evaluation is not the same as account-

ing. If we assume that profitability is the primary goal of the dairy business, then economic planning, management and analysis is about managing the dairy farm resources profitably. Finance deals with the flow of funds and measures financial performance. Economics is broader and includes concepts of valu- ing resources as they contribute to profitability. These concepts include opportunity costs, marginal analysis, equimarginal returns, input substitution, contribution margin, and the time value of money (discounting) which are not all typically considered part of financial accounting. They are, however, important in economic analysis when determining which strategies and tactics increase profit.

Tactical and Operational Decisions. Whenever there is a way to increase profitability, it is economically rational to do so, other things being equal. This means that economic planning and management requires knowing not only what is profitable, but what is most profitable, and hence the notions of opportunity cost, equimarginal return, input substitution, etc. become important. Optimization is fundamental because economics is largely the science of choice. Business goals and limited resource availability force choice. There are normally multiple production possibilities, some more desirable than others, as measured by some criteria, and it is the essence of optimization to make the best choice.

Application of economic principles, at least theoretically, requires the revenue and cost accounting of all production possibilities, and then application of the appropriate economic principles to choose the most profitable alternative. Greatest profitability occurs when the greatest difference between total input costs and revenues is achieved, not necessarily at the lowest input costs, or most efficient ratio of inputs to outputs, although sometimes, of course, these will be the same. This is fundamentally different from simply doing an accounting exercise of costs and returns. An example (Table 1 ) using opportunity cost helps to illustrate the difference between accounting and economic information. The example considers the calculation of cow profitability for ranking cows for culling on economic, not production or accounting, information.

Two popular measures of dairy cow profit, total profit (similar to “lifetime”) and average profit (similar to profit per day of herd life), are incorrectly applied for culling decisions, relying on untenable assumptions (van Arendonk, 1991 ). They are simply accounting definitions of profit, assuming that either no replacements enter the herd (total profit) or every cow is replaced by a heifer having identical characteristics as the cow leaving (average profit). The correct economic analysis considers both the future profitability of the cow and the opportunity cost of postponed replacement. Ap- proaches which do not consider opportunity cost are not correct. The correct approach eliminates confusion caused by definitions which superficially appear to make, or reflect, common sense, but on analysis are incorrect.

Strategic Decisions, Unknowns, and Risk. It has been argued that the goal of maximum profit (imply- ing optimization) forces simplifications of real world problems into computable representations of reality and assumes unrealistic omniscience with respect to site-specific parameter values, future product prices and input costs, and other model variables. Further, the decision maker’s goal may not be equivalent to a straight forward measure of profit. A more reasonable approach, it is argued, may be to

strive for constant improvement while finding satis- factory solutions for a more realistic world. Simon called this "satisficing", reasonable men making reasonable choices (Simon, 1979) in the face of com- plexity, numerous constraints, imperfect knowledge, unknowns, and risk.

It is true the dairy business is inherently risky due to the biological nature of milk and crop production, weather, input costs, and output prices. Deci- sions are also difficult because knowledge is always imperfect, information about alternatives may arrive slowly, and we often know far less than we would like about our alternatives. Actions usually create sunk costs which may be impossible to recoup and the economic environment is uncertain.

Dairy decision support methods that take advantage of optimization are most widely used for repet- itive tactical decision making such as ration balancing, sire selection, and to a lesser degree culling and replacement. Although long-term strategic decisions can be analyzed using optimization techniques, for the reasons mentioned above, simula- tions and other forecasting methods are often found useful to determined the effects of external price changes (such as milk or feed price) and other factors effecting the success of investment decisions. Variability in potential outcomes, and thus risk, is also important to try to predict. If the risk can be described, than there are methods to incorporate it

into the decision framework. Forecasting Revenues and Costs. Forecasts will

never be perfect and the activity may be more important than the result because of what it tells the planner about the business and other forces at work, but planning is a part of control. Economic and financial planning requires predicting revenues and costs. Revenues would include at least milk yield, cull cows, number of calves sold, calf income, income from sale of assets, and investment income. Costs result from feed, replacements, labor, and other inputs. Forecasting based on last year's figures is useful if the business remains substantially the same from year to year, without improvements in management, production performance, or other factors. But with this approach there is little basis to generate predictions if the herd or management changes. Modeling the herd can be useful to predict future milk production, animal sales, and required inputs, and thus produce a detailed budget for the dairy based on:

1 ). known production performance from production records, 2). the current status of the dairy, including status

of the dairy herd, 3). aggregation over all cows, and 4). constantly updated production data from the

production recording scheme as well as the cost and price data from the managerial accounting system.

Outputs of these models can be part of the integrated planning system because they create cash flow budgets, inventories, income statements, replacement forecasts and future feed needs. Also, forecasts can be changed with different price or performance outlooks to determine business ramifica- tions in a"what-if" framework. The future scenarios described are reported in financial terms to assess financial impacts. In a sense, this is a rigorous bud- geting exercise.

Useable Information Systems Decision support systems which include eco-

nomic evaluation are beginning to appear. This paper will deal with one, butthereareothers which differ in numerous ways. The purpose is to illustrate the use of combining production and financial data to generate economic information in a useful format for dairy managers, not to promote one system. Simulation and optimization are used, and the overall purpose is to provide better information to dairymen as they try to make necessary decisions to control their businesses. The specific application that will be discussed is the Florida Dairy Management Project (FDMP), because the authors are most familiar with it. The information system is called the FDM P-MIS. 1). keep,

An overview of the production and economic data collected from each dairy is listed in Table 2. These data are dairy specific and are delivered through several methods. Although not required, all current FDMP dairies are enrolled on DHlA testing and the herd production history, current herd production, and cow reproductive records are down- loaded directly from the appropriate DRPC and maintained in a database. Other data summarized by DHlA (e.g., monthly conception rates, heat detection rates, 2X 305d ME, cow mortality rates) are directly recorded/calculated from the DHI Herd Summary file. Additional data on actual milk sold per month, animal inventories, feedstuff nutrient analysis, ration composition, feed usage, etc. are provided directly by the dairy producer. Most economic data come directly from the producer and primarily consist of monthly income statements,

forecasted milk prices, feedstuff costs, replacement costs, carcass and calf prices, short-term interest rates, etc. Financial and economic data are summarized and maintained in a database.

Models. At the heart of the FDMP-MIS are two models which:

1) . are causal because they predict production possibilities based on individual cow and herd production Characteristics specific to each dairy,

2). integrate production and economic data s p e cific to each dairy,

3). base decisions on economic criteria, and 4). generate predictive and prescriptive informa-

tion for management decision making specific to the production and economic conditions existing, or predicted for, each dairy.

The first model is a dynamic programming (DP) model developed by DeLorenzo et al. (1 992). This model finds profit maximizing insemination and culling/replacement policies. It maximizes profit from each cow position in the herd. The model inte grates dairy-specific production and economic data (Table 2) to calculate the net present values for every cow. Essentially, the model makes one of three decisions for every month of a cow's life:

2). replace, or 3). if a cow is kept, and she is open, whether to

breed her at her next estrus. The decision to keep or replace considers the

opportunity cost of postponed replacement because the cow is kept only if her net present value is higher than the average first-calf heifer competing for her position in the herd. The production and economic characteristics of the first-calf heifers are based on dairy-specific data on first-calf heifers calving in the month of replacement.

The second model is a simulation model which is integrated with the DP. The simulation model predicts the herd's monthly milk production, feed costs, herd structure (total herd size, number of dry and milking cows), number of culls, number of calving, and number of pregnancies. On a routine basis (each month) two scenarios are calculated. The first

scenario is predictive and produces a forecast for the dairy under the assumption that the dairy producer will continue to follow present breeding and culling policies. The second scenario is prescriptive and produces a forecast, or goal, under the assumption that the producer is following optimal breeding and culling policies as prescribed by the DP model.

An important feature of the FDMP-MIS is the flexibility of the DP and simulation models in allowing a wide variety of possible production and economic scenarios to be examined. Dairy producers often request special scenarios examining a multitude of

possible management strategies (e.g., BST use, A.I. vs natural service breeding, etc.), alterations to farm structure (e.g., expansion, heat stress abatement structures and equipment, etc.), and changes to herd structure (e.g., timing effects of additional heifer pur- chases, etc.). The strategy of using dairy-specific data is essential to the success of the basic FDMP services and allows the special scenarios to provide meaningful information. It insures that the information received by a dairy manager has been tailored to the unique conditions found on his dairy. Accu- rate accounting data is required. The breeding and

culling model is particularly useful to account for complex seasonal patterns of milk price, milk production, and reproductive performance.

Once the herd’s production characteristics have been generated for the next 12 calendar months this information is further integrated with expense and revenue data from dairy-specific income statements. Integration of these production and economic data allow the generation of descriptive (actual/past), predictive (forecast), and prescriptive (goal) cash flow and/or income statements for the next 12 calendar months. This final link in the process allows dairy managers to ascertain the economic consequences of following current breeding and culling policies. optimized breeding and culling policies, or any proposed management change capable of being cap- tured by the DP and simulation models.

Subsidiary production and economic summaries and graphs are also prepared using spreadsheets and databases. These summaries and graphs may con- lain all levels of information (descriptive, predictive, and prescriptive) or be limited to descriptive and diagnostic information lor monitoring purposes. Such items as milk production and income per

month, purchased replacements, labor costs per cwt. of milk, dry matter intake, feed cost per cwt. of milk, etc. are summarized on a monthly basis.

Management Reports. A report received by FDMP dairy managers each month are a set of breeding and culling guides. Table 3 shows a portion of an actual breeding guide and Table 4 a por- lion of an actual culling guide. These guides suggest, for the current month, from a profit-maximizing standpoint, which cows in their herd should receive the highest priority for breeding and those that are likely cull candidates. In the breeding guide each open cow in the herd has a value (Value Insemin.) indicating the expected net discounted return from inseminating her at her next estrus versus waiting. The relative breeding values can be viewed as a priority list for breeding. Thus, cow #3019 should receive the highest heat detection intensity. The culling guide shows the net present value of keeping a cow versus replacing her with an average first-calf heifer calving in the month of replacement. For example, it is recommended that cow #6 be culled, other things being equal, even though her expected net cash return over the next

12 months is positive, because a first-calf heifer taking her position would provide a higher net present return ($1 17). These are specific reports which recommend specific herd management actions to increase farm profitabiIity.

The second set of outputs received by FDMP dairy managers each month are a set of cash flow reports reflecting the economic consequences on the dairy businesses' cash flow of following current versus optimal breeding and culling policies. In addition, actual cash flows are summarized for monitoring purposes and a variety of subsidiary production and economic summaries and graphs are prepared. Table 5 shows a reduced schematic example listing descriptive (past), predictive (forecast), and prescriptive (goal) cash flows. The revenue and expense categories in this example are highly aggregated and summarized on a yearly basis for illus- trative purposes. In reality, three cash flow reports (past, forecast, goal) are received by the dairy manager containing 12 months of information and there are up to 25 expense categories. As indicated in Table 5, following optimal breeding and culling policies for this dairy would be expected to produce a yearly cash flow over $1 06,000 higher than following current policies. Various graphs are also provided to dairy managers on a monthly basis. The graphs provide varying levels of information (descriptive, predictive, prescriptive) depending on the item of interest. Dairy managers who desire to examine possible changes in other management strategies, alterations to farm structure, and/or changes to herd structure would also be provided with a full set of cash flows, summaries, and graphs in addition to those provided on a regular monthly basis.

Human Factors. The ultimate use of the information described above IS dependent upon the in-

teractions between the dairy manager and the FDMP consultant. The reports are only one Source of information for the overall decision process. The dialogue between the dairy manager and consultant is the most important vehicle for delivering the decision aids. Initially, some dairymen more readily accept quantitative decision tools than others, although there are Some similarities across all dairy managers. One of the most important concepts that the dairy manager must understand is the dairy-specific nature of the FDMP-MIS recommendations. Once this realization occurs, the information is more meaningful than i f Only a "representative" farm were described.

Conclusions Defining management problems correctly in eco-

nomic terms is important. Production recording and accounting data need to be combined into economic information to correctly support management decisions. Interactions between various factors must be considered and models that incorporate interactions between the various components of the production system are important. Information and knowledge will always be incomplete and risk is a major consideration for decision makers, especially for long term strategic decisions. The use of causal models and optimization can generate alternatives,

and although not perfect, predictions can help steer decisions and provide some measureof risk. For tactical and operation decisions that are often repeti- tive, profit maximizing techniques are useful and can yield specific management guides suggesting specific actions, although other information must always be included as well.

Managing Conflict In Agricultural

Business

Conflict is a daily reality for everyone. Whether at home or at work, an individual’s needs, goals, objectives and values constantly and invariably come into opposition to other desires held by our- Selves or others. Some conflicts are relatively minor, easy to handle, or capable of being overlooked. However, others of greater magnitude require a mindful strategy for successful resolution if they are not to create constant tension or lasting enmity in ourselves our homes or farm business.

Conflicts left unresolved and festering at the expense of the business and individuals well being are an all too common occurrence in agriculture and other small business. The ability to successfully resolve conflict is probably one of the most important personal and business skills an individual can possess. In spite of this fact there are few formal opportunities in our society to learn effective conflict management. This is partly because we do not understand conflict due to its complex nature, and partly because even if we understand conflict, and have a good inner working model of what is happening with ourselves and others in a conflict situation, that is still only a small percentage of the knowledge necessary to master to manage conflict. The next step is the development and use of interpersonal communication skills that will allow us to accelerate or decelerate conflicts to resolution.

Like any other human skill, conflict resolution can be taught; like other skills, it consists of a number of important subskills, each separate yet interdependent. These skills need to be assimilated at both the cognitive and the behavioral levels (i.e.,Do I under-

stand with my mind how the conflict may be resolved and do I have sufficient mastery with interpersonal skills and behaviors to affect positive change toward resolving specific conflicts?). To learn how to manage conflict, we will first build working definitions of conflict terminology and working models for thinking about and managing conflict. With these models in place, we will move to a discussion of some specific interpersonal conflict resolution skills.

Terminology The terminology we will use in the discussion of

conflict follows: Conflict- A type of problem involving the colli-

sion or opposition of ideas, objectives /goals. Content Conflict - A difference of opinion or

clashing objectives/goals on substantive, content, formal task or procedural matters.

lnterpersonal Conflict - Content disagreement plus negatively charged conflicting interpersonal relationship issues may occur in dependent, formal interpersonal relations, or independent, informal interpersonal relationships.

Conflict is not good or bad. Conflict usually holds the potential to be either, and must be carefully managed to assure the desired outcome. The following list outlines both potential outcomes of conflict.

Good Side of Conflict Properly managed, moderate doses of conflict

Conflict is the root of change. People learn and grow as a result of conflict.

can be beneficial.

. Conflict stimulates curiosity and

Conflict helps to relieve monotony

Conflict can provide diagnostic

After conflict, closer unity may be

imagination.

and boredom.

information about problem areas.

re-established. Bad Side of Conflict

Prolonged conflict can be injurious to your physical and mental health.

Conflict diverts time, energy, and money away from reaching important

. Conflict often results in self interest

Intensive conflict may result in lies

goals.

at h e expense of the organization.

and distorted Information. Conceptualizing Conflict

Conflict can result from substantive differences, that is, differences resulting from objectives, structures, policies, or practices; or it can grow out of personal or emotional differences that occur between people Another way to examine conflict is to look at differences in four categories: facts, methods, goals and values.

These different viewpoints may exist because of differences in individuals' informational exposure (for example, reading different articles in professional journals), their perception, or the roles or posi- lions they hold.

I t can be useful to view conflict ascyclical. Overt conflict might occur only periodically when people's contrary values or goals surface through an activating event. The underlying issues may lie dor- mant for a while before something happens to trigger a conflict episode. Once triggered, the expressed conflict will usually become less pronounced over time, and the issues may not be apparent until the next triggering event causes the cycle to repeat itself. Richard Walton (1987) studied conflict cycles and identified four basic elements: issues, triggering

Issues are the substantive, content or interpersonal emotional differences that underlie any conflicting relationship. The triggering event (which may be significant or very minor) causes the latent conflict to be explicitly expressed. The behavior dis- played by the conflicting parties leads to the consequences of the exchange. Issues or triggering events may change from one cycle to the next, and the consequences may differ significantly. A conflict cycle may escalate, indicating that the relationship is become more conflicting over time. An example of this might be a deteriorating marriage in which the husband and wife begin to fight more frequently and seriously.

A conflict cycle may also de-escalate, indicating that the individuals involved are learning to adjust and work successfully, despite their differences.

In addition to events that trigger a conflict episode, there may be barriers that inhibit the open

I . . events, conflict behavior and consequences. expression of conflict For example

may be afraid of hurting the other person's feelings, or the culture of a particular organization may value teamwork and camaraderie so much that members stifle any potential conflict. If barriers exist and conflict still manifests itself, i t may indicate that issues or triggering events are more significant than the barriers.

When successful confrontation and resolution is the goal of managing conflict, many underlying issues may be eliminated. Controlling conflict is another viable goal. In controlling conflict, most of the issues still exist but the negative consequences are minimized. One can control conflict by rein- forcing the barriers to conflict or by preventing a triggering event from occurring. This emphasizes the importance or prior analysis of a conflict situation to determine what these elements are.

The Formal And Informal Organization Like plants and icebergs, organizations cannot be

totally seen or understood from the surface. We will briefly describe two dimensions of organizations, one above and one below the surface, to facilitate our understanding of leadership and conflict. A manager must be aware of how and be able to oper- ate in both components of the organization lor effective interpersonal conflict management to occur. Note carefully the distinction made in the model.

Context Issues Diagnosis Diagnosing the context of a conflict is the start-

ing point in any attempt at resolution. The most important issue which must be decided is whether the conflict is an emotional, informal, interpersonal ideological (value) conflict or a formal, content (tangi- ble) conflict - or a combination of both. The distinction between issues of content and those of an interpersonal nature is a most useful and important one to make to then be able to rationally decide the best strategy and tactics to use on order to come to reso-

lution. The following models are useful in determining the extent to which a conflict is content and/or interpersonally comprised.

Power Diagnosis The next issue to discuss in light of conflict is the

issue of power or the lack of it. Careful diagnosis of the balance of power in a conflict will aid us in determining a resolution strategy. This discussion of the sources of power and authority is imperative if we are to understand organizational and interpersonal dynamics and be able to resolve conflicts. Power is described as influence potential: it is this resource that enables one person to gain compliance from or influence over others.

Given this integral power relationship that exists between people, managers must examine their possession and use of power in conflict situations. One can imagine that if a fight were to break out you would put your money on the largest person or the one you thought had the most power and would be most likely to win the conflict. In the case of interpersonal conflicts win/lose situations are not always appropriate and so the use of power or the equal- ization of power must become a management decision depending on the desired result. The sources of power reviewed in the previous exercise may come from both the formal organization and the informal sides of organizations just as conflict issues do.

These bases of power are important to understand to consciously decide to use or not use power in a given situation. The possession of power or the lack

of it may profoundly affect a person's behavioral response to a conflict situation. People must be empowered if your goal is to utilize collaboration or negotiation as a means of resolution.

Balance Of Power In A Conflict

Diagnose the context of the conflict and determine who has the power in a conflict sit-

uation and from what source that power comes. Further, ask if the power is in balance or out of balance. This is not to say that the power should always be equalized to reach resolution. That will depend upon how you decide to handle the conflict. It may be that in a given situation you decide to increase the imbalance of power.

A. Coercive power is based on fear. A leader scoring high in coercive power is seen as inducing compliance because failure to comply will lead to punishments such as undesirable work assignments, reprimands or dismissal.

B. Connection power is based on the leader's "connections" with influential or important persons inside or outside the organization. A leader scoring high in connection power induces compliance from others because they aim at gaining the favor or avoiding the disfavor of the powerful connection.

C. Expert power is based on the leader's possession of expertise, skill, and knowledge, which, through respect, influences others. A leader scoring high in expert power is seen as possessing the expertise to facilitate the work behavior of others. This respect leads to compliance with the leader's wishes. D. Information power is based on the leader's

position of, or access to, information that is perceived as valuable to others. This power base influences others because they need this information or want to be let "in on things."

E. Formal power is based on the formal position held by the leader. Normally, the higher the position the higher the legitimate power tends to be. A leader scoring high in legitimate power induces compliance from or influences others because they feel that this person has the right. by virtue or position in the organization, to expect that suggestions

will be followed. F. Personal power is based on the leader's per-

sonal traits. A leader scoring high in referent power is generally liked and admired by others because of personality. This liking for, admiration for, and identification with the leader influences others.

G. Reward power is based on the leader's ability to provide rewards for other people. They believe that their compliance will lead to gaining positive incentives such as pay, promotions or recognition.

The Technical Components: People, Process And Context

We must look in depth at some technical issues involved in conflicts and establish some models for understanding them. All conflict situations differ. Therefore, we can never assume that all of them can be resolved in a reasonable constructive manner. Nor should we always see conflict as a life and death, win or lose struggle. Each situation should be seen on its own terms. As we look at conflict from the point of view of resolution, we will consider the following issues: the people involved, the context of the situation and the process.

PEOPLE 1. Characteristics of the parties involved

values, motivations, aspirations, objectives physical, intellectual, social, emotional, spir-

itual development beliefs about conflict, conceptions of strat-

egy and tactics

default conflict behavior patterns integrated or polarized

attitudes, beliefs, expectations about one another

beliefs about other’s view of oneself degree of polarization (How far apart are

they?) 3. Consequences of conflict to each participant

gains and losses (wins and losses) precedents set for the future changes as a result of conflict

restraints, encouragements, deterrents and social norms concerning strategy and tactics

. relationships to the individuals involved 2. Prior relationships to one another 3. Interested audiences to conflict

Conflict-Management Styles (Adapted b y Guy K. Hurt from

Martin B. Ross 1982 Annual for Facilitators, Trainers, and Consultants)

The ability to cope successfully with conflict is among the most important social skills one can acquire. As people mature they usually develop behaviors for coping with conflict; there is even some evidence that they develop certain preferred styles (Thomas & Kilmann, 1974). Almost invariably, conflict-management skills are acquired without formal education or guidance. Usually behaviors are modeled after the behavior of others. If one is fortunate enough to have good models, and if one is lucky enough to be in situations in which the modeled style is effective, one is usually successful. If not, one may learn an effective style too late. The best way to minimize failure is to learn what styles are available, in what situations they are most effectively employed, and how to use them.

The model of conflict patterns developed for this paper, based on the earlier work of Thomas (1 976), provides an excellent framework for learning various conflict-management behaviors, their situation-

PROCESS 1. Strategy and tactics employed b y parties involved (extent of use) . promises and rewards

threats and punishments . freedom of choice/coercion openness of communication and sharing of

information avoidance approach

CONTEXT 1 . Nature of issue giving rise to conflict . scope, rigidity, significance frequency

formal -task - content informal - interpersonal

2. Social environment within which conflict occur

. --

specific assets and liabilities, and the consequences of using a particular style too little or too much. As shown in the model, two basic variables are plot- ted against one another (1) assertiveness, the extent to which the individual attempts to satisfy his or her own concerns, and (2) cooperativeness, the extent to which the individual attempts to satisfy the other person’s concerns. These two dimensions define five distinct styles for coping with conflict: competition, collaboration, avoidance, accommodation and compromise.

Which Pattern Or Style To Use Nothing is inherently right or wrong about any of

the conflict-managemenl styles; each may be more or less appropriate and effective, depending on the situation and the parties involved.

Each of us has access to a variety of conflict-management behaviors but we tend to perceive certain ones and use them to the exclusion of others that could be more effective in a given situation, often with adverse consequences. We must develop the

skills to execute any of the styles. Then we can diagnose conflict situations and choose the appropriate way to deal with whatever come up, depending on our needs at the time and the importance of coming to a resolution within a prescribed time frame.

Whether a particular conflict-management pattern or style is appropriate is specific to the people and context of the conflict situation. To be effective at managing conflict, one should be able to use any of the styles and know when each style is appropriate. However, people tend to develop one preferred or default style and use it in most situations. As a consequence, people may neglect styles that could be more effective.

Steps For Collaborative Conflict Resolution 1 . Explain the situation the way you see it.

Emphasize that you are presenting your perception of the problem. Specific facts and feelings should be used if possible. 2. Describe how it is affecting performance. Keep

attention on the work-related problem and away

from the personalities involved. Present the problem in a way that will be readily understood, and concentrate on important issues.

3. Ask for the other viewpoint to be explained. Before proposing solutions, gather as much information as possible. This step confirms that you respect the other person's opinion and need his or her cooperation. Listen carefully while he or she talks and be open to learning and changing. 4. Agree on the problem. Summarize the various

viewpoints and state clearly the problem that you and the other participant(s) think needs to be solved. Once both parties agree on this, they can more easily focus on developing solutions.

5. Explore and discuss possible solutions. To ensure shared ownership of the problem's resolution, all participants in the conflict should be involved in developing solutions. The synergy developed may result in better solutions that any participant would have produced alone. 6. Agree on what each person will do to solve the

problem. Every person involved must clearly understand his or her role in the solution and accept responsibility as an individual and team member for making it work. 7. Set a date for follow-up. A follow-up meeting

allows you to evaluate progress and make adjustments as necessary. People are much more likely to follow through if they know they will be held accountable for their commitments at a follow-up meet i ng.

Some Communication/Process Requirements For Successful Conflict Resolution

1. Focus is on defeating the problem, not one

2. Everyone is involved in the process to create a

3. Solutions are evaluated in terms of quality and

4. Questions are asked to elicit information, not

5. Feedback is descriptive, specific and non-judg-

6. Power is equal or power differences are

ignored. 7. Information is shared equally by everyone. 8. Parties believe that mutually acceptable solu-

9. Parties trust each other, are not defensive, angry

10. Parties do not make a "we-they" distinction;

11. Problems are jointly defined by the parties. 12. Problem description, solution generation and

solution evaluation are separate phases of discussion.

Key Learning Points Conflict has both positive and negative conse-

quences for an organization and for an individual. The absence of conflict can by as dysfunctional as excessive amounts of conflict.

There are five basic conflict styles, all of which have potential uses. Choosing the appropriate style to use depends on the situation at hand.

Thoroughly analyzing a conflict situation is vital to ensure that an appropriate resolution strategy is used. Control and confrontation are both legitimate strategies.

tions are possible and desirable.

or threatened.

instead it's "we vs. the problem."

another.

sense of shared responsibility for the solution.

acceptance to the parties.

to belittle the other party.

mental.

EconomicImpact of BullChoices... A.I.Or Otherwise

By Dr. Ben McDanielAnimal Science Department

North Carolina State UniversityP.O. Box 7621

Raleigh, NC 27695-7621919-515-4023

fax 919-515-7780Email: Ben [email protected]

2ND WESTERN LARGE HERD DAIRY MANAGEMENT CONFERENCE • LAS VEGAS, NV • APRIL 6-8, 1995 1 3 3

PP rofitability from bull selection and otherreproductive technologies such as embryotransfer will vary from herd to herd. Much of

the differences will depend on how carefully theeconomic consequences of the various decisionsmade when choosing among alternatives are eval-uated. For instance, if the highest-priced bulls areused under the assumption that semen price is al-most perfectly correlated with true value for com-mercial milk production, profitability from the selec-tion program will be low and probably nonexistent.Using natural service just because it is perceived toalways be more cost efficient will often lead to lessprofitability than use of A.I. Provided that replace-ment heifers are to be reared fromcalves born on the farm, a care-fully planned A.I. program usu-ally, but not always, will be themost profitable breeding strategy.

One of the few exceptions tothe potentially superior profitabil-ity of A.I. would occur if replace-ments of equal quality can be pur-chased cheaper than yours can bereared. Whether A.I. should bepracticed in such a situation woulddepend on its effect on sale priceof calves a few days old comparedto any extra costs of A.I. over nat-ural service and safety considera-tions. The latter may be importantif dairy bulls are used naturally.

Another caveat is that commonsense is used when buying and using semen. Buy-ing semen from the currently “hot” and usually over-priced bulls to breed ordinary grade cows is not sen-sible. Despite the hype that usually surrounds suchbulls, few if any will sire the most profitable com-mercial replacements. Some may, however, win thelocal cattle shows but how many commercial dairyproducers show cows today?

Using expensive semen to inseminate cows thatare likely to be culled before they calve again or thoseof low or questionable fertility does not fall within my

definition of common sense either. Breeding heifersto bulls known to cause a high percentage of difficultbirths of 10% or higher is in the same category.

How should semen be chosen to maximize prof-itability? The best procedure is to use an index suchas Net Merit published by USDA as the first screen.First, this measure includes a bull’s genetic valuesfor milk, protein, and fat minus the feed costs neededto obtain the extra outputs. If the ratio of yourexpected FUTURE prices for protein and fat differsfrom the national averages used by USDA, it is a rel-atively simple matter to adjust for your market.Please note that unless the ratios of prices amongmilk, fat and protein change there is little advantage

in recomputing the index. Even ifyou plan to breed or buy bulls touse in natural service, you shouldapply the same procedure to theirpedigree values to decide whichones to use.

The second part of the Net Meritindex, PTA for Productive Life, alsohas major economic value. Longerproductive life means both moremonths of production per cow andfewer replacements, thereby dilut-ing the net cost of replacementsper lb. of milk produced. TheUSDA PTA for this trait for Holsteincows also takes account of theeffect of type traits on survival ratesor longevity, a modification that isespecially valuable for bulls with

only young daughters.The PTA for Somatic Cell Score (SCS), the third

part of the Net Merit index, will almost surely bemore important in the future than it is now weightedin the index. This statement is made because recentresearch at North Carolina State shows that daugh-ters of bulls with desirable (low) PTAs for SCS livelonger than those with higher values. Our resultsshowed PTA-SCS to be slightly more closely relatedto length of life than PTA-Milk was. The value of ahigher survival rate is not now included in the value


Economic Impact Of Bull Choices... A.I. Or Otherwise

Provided thatreplacement heifers

are to be rearedfrom calves born onthe farm, a carefully

planned A.I. pro -gram

usually , but notalways, will be the

most profitablebreeding strategy .

assigned to PTA-SCS in the Net Merit equation. Also,quality premiums for low SCC milk and penalties forhigher SCC are almost surely to increase in the future.

Admittedly, we have much to learn about theoptimum use of PTA-SCS, but I am convinced thatthe more we learn, the higher the economic valueof the trait will become. This does not mean that wewill control clinical and subclinical mastitis bygenetics, but simply that it will become part of thestrategy for keeping them minimized.

Recent research at Virginia Tech has verified theconsiderable economic value of conception rate ofsemen. The limitation to using the currently availablemeasure of it, Estimated Relative Conception Rate(ERCR), is that it can only be computed accuratelyafter the bull has been in service for a year or two.

Differences of 5% in ERCR are common amongactive A.I. bulls. To put this in perspective, the trueconception rate of Holstein cows is usually 40-50%.An ERCR of +5 means that 5 more cows per 100serviced will become pregnant, a true advantage ofat least 10%. This translates into about a 10% reduc-tion in the cost of a conception, not an insignificantamount. Holstein heifers are more fertile, perhapsas much as 65-70%, so ERCR is not quite as impor-tant when breeding them, but a 5% difference stillis not trivial. Provided calving difficulty of a bull isnot too high, the most profitable place to use bullswith many desirable traits, but a below-averageERCR, is to breed them to heifers.

Breeding heifers to bulls siring calves that areborn with little difficulty (7% or lower calving diffi-culty) is an economically desirable practice pro-vided not too much is given up in other traits. Luck-ily, low calving difficulty, high milk and high sur-vival are favorably correlated. The younger heifersare bred, the more important it is to chose for lowcalving difficulty among bulls high on Net Merit.However, it does not make sense to sacrifice every-thing else to get low calving difficulty if the result-ing heifers are to be reared as replacements.

In the past it was commonly thought that breed-ing to a beef bull was a surefire way to have lowcalving difficulty. Today, many beef bulls cause

much calving difficulty and must be chosen as care-fully as dairy bulls to reduce it.

Even if replacements are not to be saved, remem-ber that losses are higher in heifers having calvingdifficulty from increased deaths, personnel costs,lower milk, and poorer rebreeding rates. This meansit is profitable to choose bulls to minimize calvingdifficulty when breeding heifers. This holds regard-less of what type of bull – A.I. dairy, A.I. beef, nat-ural service dairy or beef – is used.

Bull choices that will lead to inbreeding usuallywill be less profitable than those giving outbreed-ing. Matings that will produce inbred fetuses havea reduced success rate. A fetus that is inbred has upto a 50% higher chance of dying before birth thana non- inbred one. A common misconception is thatinbreeding only affects calves after they are born,but the truth is that the detrimental effect starts theday an inbred mating is made. Conception ratesfrom inbred matings will be lower, as well as sur-vival to implantation and any later stage of preg-nancy. Bluntly, the economic effects of inbreedingin dairy cattle are often underestimated. Just ask anypig or beef producer why they usually crossbreedand you will find out why.

My rule of thumb is that for an inbred mating tobe justified the predicted economic value of a result-ing calf has to be at least 1% higher than the bestnon-inbred mating for each 1% more inbreedingthat it will cause. I challenge anyone to provide databased on a complete economic analysis that refutesthis. Analyses based on “inbred” cows that surviveto lactate have ignored most of the true costs ofinbreeding. An advantage of A.I. is that many bullsrepresenting a wide variety of lines are available, soinbreeding can be minimized.

One of the false ideas used to support natural ser-vice is that it is practically free. This false idea arisesbecause all direct costs of using bulls are rarely con-sidered, let alone the indirect and opportunity costs.Research several years ago at the University of Wis-consin by Shook showed that the direct costs of nat-ural service in a typical herd averaged $18 per ser-vice. With the larger herds typical today, this may


George Brandsberg

5

George Brandsberg

be a few dollars too high, but nat-ural service is still costly. Low con-ception rates and diseases mayalso be obtained from such bulls.

Among the indirect and usuallyignored costs of natural serviceover A.I. are more inbreeding andimprecise knowledge of expectedcalving dates. Unless cows can begrouped by their genetic relation-ships, which is impractical in mostherds, some inbred matings willbe made leading to the losses dis-cussed earlier. If expected calving dates are notknown, dry periods will not be of the economicallybest length. Also, dry cows will not get the man-agement necessary to maximize future profitability.

For A.I. to be profitable, management adequateto detect accurately at least 40-50 percent of trueheats is essential. Without this minimum level ofaccuracy, a high percentage of cows will be misseduntil their lactation is advanced. Obviously, longopen periods predispose a cow to premature culling.

A common misconception is that 70-80% ofheats must be detected to use A.I. successfully. Actu-ally, only the best managed herds reach that level.Studies by Blake and colleagues at Cornell showedthat increasing accurate heat detection rates beyond50% was often unprofitable. This occurred whencosts to obtain the extra accuracy amounted to morethat a few dollars per additional cow detected.

Accurate identification of individual cows is alsoessential. Otherwise, cows may be misclassified asin heat when they are not. Inaccurate identificationof the cows truly in heat usually has drasticallyunprofitable effects. Results will be unnecessarycosts without additional pregnant cows. Breedingcows not in heat may also be harmful to the futurereproductive success of a cow and provides zeroreturn on semen and other costs.

Consequences of inadequate or inaccurate heatdetection will be costly. Long calving intervals willbe common. Yields of many cows will decrease tounprofitable levels before they become pregnant.

Combined, these may negate someof the favorable aspects of A.I.

Limitations of facilities mayaffect the profitability of A.I. Whenit is expensive to catch and restraincows for breeding, costs per preg-nancy increase. If catching andrestraint upsets cows, conceptionrate can be reduced. This mayreduce the pregnancies resultingper A.I. service, thereby increasingtheir cost. New Zealand, whichhas one of the world’s lower fixed

cost per cow, breeds nearly 70% of its cows by A.I.This shows that adequate facilities for A.I. need notbe expensive.

Another common misconception is that concep-tion rate to A.I. service must be over 50% for A.I. tobe profitable. At 40% conception, only 34% of cowswill require three or more services. Only 10% willneed more than four inseminations. The realisticupper limit of conception rate is only 65-70% withnatural service to a highly fertile bull. For example,pregnancy rate is rarely more than 80% in cyclingcows exposed to a fertile bull for 50-60 days. Usu-ally higher conception rates will make A.I. moreprofitable, but an outstanding conception rate is notnecessary to make A.I. more profitable than naturalservice.

The opportunity costs of using natural service arewell known. The USDA summaries released afterevery sire summary show that the net value of theextra milk of an A.I.-sired cow is worth at least $25over feed costs in each of her three or more lacta-tions. This occurs because feed costs for maintenanceand fixed costs are nearly the same for every cow ofthe same age and body size. The total additional netof $75 per cow over her life should be mostly profitbecause costs of A.I. can be kept near that of naturalservice by good planning and management.

How much one can profitably pay per unit ofsemen over the cost of natural service has been thesubject of much research and discussion without ananswer that satisfies everyone. General agreement



Research severalyears ago at the

University of Wis-consin showed thatthe direct costs ofnatural service in a

typical herdaveraged $18 per

service.

George Brandsberg

136

George Brandsberg

has been reached that the expected net financialreturn from the resulting heifers is the best methodof computing how much can be paid. Disagreementstill remains on details of some of the minor costsand returns that should be included.

The main factors affecting expected or predictedincome are:

1. Expected additional lactation yield of a cowresulting from the semen of a particular bull.

2. Future values of milk and its components.3. Expected length of a resulting cow’s produc-

tive life.4. Conception rate of semen as it affects the prob-

ability of a heifer calf.5. Values of any traits such mastitis resistance,

ease, labor or speed of milking, calving difficulty,etc., that reduce costs over that of an average cow.

The main factors affecting variable and A.I. costsare:

1. Expected future feed costs per unit of milk andcomponents.

2. Minimum cost of getting a cow pregnant byA.I. minus cost of a pregnancy from natural service.

3. Extra cost of semen from a particular bull nec-essary to obta.n a milking heifer, discounted for thetime value of money.

4. Opportunity costs from any milk lost due to calv-ing intervals longer than those from natural service.

You may note that only the additional cost ofsemen is affected by conception rate. Whether thecow will be kept to calve, calf liveability, and allother costs affect A.I. and natural service equally

Comparing Profitability of A.I. andNatural Service for a Herd:

A simple but reasonably accurate comparison ofthe relative profitability of A.I. and natural servicebreeding may be obtained by the following steps.Estimate or compute the following:

• Expected value of milk and its components in yourfuture milk market for a lactation from an averagedaughter of the A.I. bulls available, minus the val-ues for an average natural service daughter. Multi-ply by 3.0 for lifetime value.

• Add in the value of superiority for additional traitsof the A.I. bulls, including udders, feet, SCS, andlongevity . Multiply by 3.

• Compute value for feed costs of the extra milk,which usually varies from 35-40 % of the milk value.

• Compute the costs of getting an A.I.-sired heiferminus the cost of a naturally sired one.

The approximate profitability of A.I. for your herdis simply:

Number of replacements per yeartimes [(1 above)+(2)-(3)-(4)]

or:Number of replacements x (milk $+ $value ofother traits minus feed costs for extra milk

minus extra cost of an A.I. daughter).

For example, suppose the following costs andreturns are appropriate for your herd:

a. Many studies have demonstrated the geneticsuperiority of A.I. bulls over those used in naturalservice. Daughters of first-proof A.I. young bullsaverage about 400 lbs. more milk than those of first-proof natural service bulls from USDA summariesbased on differences in USDA PTAs. This is worthabout $40. For a lifetime multiply by 3.0 to equal$120.

b. Suppose superiority in other traits adds $15 percow over her life.

c. Suppose extra feed costs are 40% of milk, or$48 over the cow’s life.

d. Suppose the extra cost of obtaining an A.I.daughter is $50. This would include the extra laborand supplies over natural service costs.

The net value of A.I. is now $120+$15-$48-$50,for an advantage of $37 per cow. For 100 replace-ments the total would be $3,700. This does notinclude any additional value the A.I. daughter mighthave for other traits or if sold as a replacement. It alsoassumes that there is not any value in knowing whena cow is due to calve, a bit of information I believemost producers would agree has some usefulness.

2ND WESTERN LARGE HERD DAIRY MANAGEMENT CONFERENCE • LAS VEGAS, NV • APRIL 6-8, 1995

George Brandsberg

137

Let us now see if the $50 extra cost of getting anA.I. daughter is reasonable. Assuming the cost of thenatural service bull is $12 per service, and 5.0 ser-vices are required to get a milking heifer by naturalservice, base breeding costs are $ 60.

Now let us look at A.I. costs. Because our exam-ple is based on only using young A.I. bulls, thesemen cost per service would not be more than $5and probably less. Assuming other A.I. costs are $9per service, and 8.0 services are needed because oflower conception rate, we have an overall cost of$110. This totals $50 more for the A.I. heifer. The

costs used are probably too low for natural serviceand too high for A.I., but it still appeared to be moreprofitable. I believe A.I. to be a profitable investment.

In my opinion this simple example justifies myopening statement that A.I. will practically alwaysbe more profitable than natural service if replace-ments are to be saved.

The same general procedure can be used to com-pare any groups of bulls, or even two individual bulls.


notes


Managing TheMilking Parlor For

Profitability

By Craig V. ThomasDepartment of Dairy and Poultry Sciences,

University of Florida904-392-5594

fax 904-392-5595

By Dennis V. Armstrong,Animal Sciences Department,

University of Arizona602-621-1923

fax 602-621-9435

By John F. Smith,Department of Animal Science,New Mexico State University

505-646-6404fax 505-646-5441


By Mike J. Gamroth,Department of Animal Science,

Oregon State University505-737-2711

fax 503-737-4423

By David R. Bray,Department of Dairy and Poultry Sciences,

University of Florida904-392-5594

fax 904-392-5595

he trend toward larger dairy farms is occurring in every region of the U. S. For exam- T ple, in the two largest dairy states, California

and Wisconsin, average herd size since 1950 has increased 950% and 290%, respectively (5). Simi- lar trends can be seen in most other states. Today dairy herds in excess of 500 cows are common in all parts of the U. S. and herds over 1,500 cows are quite common in the Southeast and West.

An important factor which determines maximum herd size on the majority of large dairy farms is the number of COWS which can be milked per day by the milking parlor. Therefore, selecting milking parlor size in new or renovated facilities is an important business decision which will impact the volume and profitability of the dairy operation for many years. In theory the formula for profitable milking is simple: combine optimal quantities of genetically superior dairy cows with properly designed milking equipment and facilities manned by highly trained and motivated employees. However, in practice the information available to guide dairy owner/managers in predicting the level of economic performance to anticipate from various parlor sizes and designs is scarce and confusing. Also, very little is available describing the best parlor management strategies (i.e., milking procedures, amount of milking labor) required to insure optimal return from the milking parlor investment.

Recent research at the University of Florida7 8 1 1

has focused on integrating production and economic variables to determine more profitable dairy management strategies. This paper will focus on research investigating milking parlor profitability" 11 Several common decisions the dairy owner/manager must consider in order to achieve maximum mi I king operation profitability will be examined, including:

1 ) pre-milking hygiene routine, 2) level of milk production,

3) milking frequency, 4) parlor size and configuration. Double-20 and double-40 parallel parlors, which

are Common on large dairies, will be used in all comparisons.

Materials And Methods It is nearly impossible to apply traditional exper-

imental methods to complex systems like milking parlors. Also, it is not economically feasible to alter operating parlors to answer a variety Of "what-if" questions. Therefore, we examined milking parlors using a technique called simulation modeling. Sim- ulation modeling is a technique in which the real system (i.e., milking parlor, milking system, cows, and milking personnel) is imitated by a computer program- The computer program contains all of the logical and quantitative relationships between the milking parlor, milking system, COWS, and milking personnel necessary to provide an accurate abstrac- tion of the actual milking parlor system.

Our parlor simulation model8 was built from data collected from over 60 large dairies. These data included survey data and over 100 hours of video- tapes of large milking parlors in operation. The parlor simulation was validated by comparing it with the actual performance of parlors on four large Florida dairies. Table 1 indicates that the parlor simulation model was extremely accurate in predicting actual parlor performance for each of these four dairies with less than .5% difference between actual and simulated averages for number of cows milked per hour (CPH) or pounds of milk harvested per shift

(MPS) on 3x/d milking. The parlor simulation model was capable of

examining the effects of milking parlor design (herringbone vs parallel), milking parlor size (double- 16 to double-40), milking system operating characteristics (vacuum: 12.5, 13.8, and 15.0 in Hg; pulsation ratio: 5050, 6040, and 70301, milk yield, amount of milking labor, and milking procedures on milking parlor physical performance (i.e,, cow throughput and milk output).

Additionally, a capital budget model was formu- lated6 to examine the long term economic implications of selecting alternative parlor sizes, designs, and operating strategies. The budget model calculated the after-tax net present returns to ownership and non-parlor fixed costs (NPR) over a 15 year life- span for each parlor. This budget model accounted for all revenues (e.g., milk, cull cows, and calves), all variable costs (e.g., feed, replacements, utilities, parlor supplies, veterinary and medicine, breeding, milk marketing, repairs, etc.), and all fixed costs (e.g., parlor construction, insurance, property taxes, etc.).

Costs of totally equipped parlors are given in Table 2. All economic results reflect Florida’s seasonal milk price and production and all comparisons were made at a 21,000 Ib rolling herd average milk production.

The studies reported in this paper examined four issues relevant to theoperation of large milking parlors: 1 ) pre-milking hygiene routine, 2) level of milk production, 3) milking frequency, 4) parlor size and configuration. Each issue was examined for its effects on parlor physical and economic performance. Two pre-milking hygiene routines compared were: 1 ) a full routine (Full) which included stripping, pre-dipping, drying with cloth or paper tow- els, and unit attachment, and 2) a minimal routine (Min) which only consisted of unit attachment. Both routines employed post-dipping.

RESULTS Pre-milking Hygiene Routine

The decision of an owner/manager to incorporate a certain pre-milking hygiene routine is usually

determined by facility design and animal health (mastitis) concerns. Previous comparisons of CPH reported by Armstrong et al. (2) in parallel parlors showed that the full routine (Full) reduced parlor performance by 1 5-20% in double-20 to 24 parallel parlors. In the comparisons reported here cows were milked 3x and RHA was 21,000 Ibs/cow. Our pur. pose is not to recommend one pre-milking hygiene routine over another, but to give dairy owners/managers an indication of the effect! the two routines have on parlor physical and economic performance.

Table 3 presents the effects of the two routines on physical performance (CPH) and economic performance (NPR) for Full and Min pre-milking hygiene routines. Parlor physical performance (CPH) In- creased as the time required for pre-milking hygiene

the Min routine eliminates pre-milking tasks that

the Min routine was substituted for the Full routine,

CPH) and 39% in the double-20 (1 86 vs 258 CPH). Higher physical performance (CPH) resulted I n

more milk output per day with a corresponding Increase In parlor economic performance (NPR). The Iifetlme return potentials for either Parlor Increased over $1,250,000 by switching to the simpler routine. The percentage Increase in performance for larger parlors to Min premilking routine will be less than smaller parlors. This is due to the fact that larger parlors are generally less efficient than smaller parlors because they have a greater opportunity for a breakdown in milking routine and any problems will delay the turn around time of more cows in the large versus small parlor.

Level of Milk Production Rolling herd averages increase yearly I n most

dairy herds. Fifty pounds of milk per milking COW

was an acceptable average in the 1950-60's. How- ever, future levels of average m i l k production per milking cow will exceed 90 Ibs or more. Research

(9) has shown that milking time is heavily influenced by milk yield per cow. For example, a 1986 study (1) showed that the physical performance (CPH) of a double-8 herringbone decreased 25% when milk yield per cow Increased from 35 to 61 Ibs./cow/day. Therefore, it is extremely Important for dairy own-

or renovated parlors to accommodate the increased

expected life of the parlor.

25,000 Ibs.) and milking frequency (2x or 3x) on parlor physical performance and parlor gross returns per month. Pre-milking hygiene in the double-40 and double-20 was Full. The results in Table 4 show that parlor physical performance was only slightly affected when RHA increased 3000 Ibs. In the double-20 and double-40 parallel parlors there was almost no change i n CPH for 2x milked herds when RHA increased from 22,000 to 25,000 Ibs, and about a 2.5% decrease when RHA increased for 3x milked COWS. A 2.5% decline in parlor throughput may appear small; however, if herd size is around 3000 cows it means you can milk 75 less cows per day. When the income from these 75 cows is lost there is no corresponding reduction in parlor fixed costs and a nearly imperceptible reduction in variable costs. Furthermore, a change from 22,000 to 25,000 Ibs on RHA is only about a 14% increase. The percentage increase in RHA over the 15-year life of a parlor investment should be anticipated to be much higher,

decreased (Min). This is expected because going to

require over 8 seconds per cow to perform. When

CPH increased 21 % in the double-40 (317 VS 383

ers/managers to select milking parlor size for new

levels of milk production anticipated over the

Table 4 shows the effect of two RHA (22,000 and

ity to the anticipated milking frequency. Investiga- tion of parlor gross returns (Table 4) showed, as expected, that more gross income is generated by higher RHA, but gross income IS also increased by milking 2x versus 3x because more total cows can be milked 2x. Labor costs were the same on 2x and 3x because the total shift length, including set-up and clean-up, resulted in 24 hour/day parlor operation. Also, parlor fixed costs are unaffected by milking frequency. However, a 2x dairy would generate more costs due to larger land base requirements, expanded housing facilities, and greater waste disposal requirements due to the expanded herd size. Further economic studies of 2x versus 3x on large herds are needed, because even if profit margins on 2x cows are lower, total profit may be larger if parlor throughput can be increased to adequate levels to accommodate larger herd sizes.

Parlor Size and Design

Milking Frequency Machine-on time is greater per milking for 2x

cows compared to the same cows milked 3x due to higher milk yield per cow per milking. However, 3x cows have a lower average flow rate due to lower milk yield per milking. Data from several double- 20 and 30 parallel parlors has shown that steady state throughput is 8-1 0% higher for herds milked 3x versus 2x²'. A previous study evaluating the economics of 3x versus 2x milking', indicated that a response of 12-1 5% and a milk price over $1 4/cwt was necessary for 3x to be more profitable than 2x. This study did not consider fully utilizing parlor capacity to maximize parlor output.

Table 4 shows there were large decreases in CPH when milking frequency went from 3x to 2x at either RHA. Going from 3x to 2x at 22,000 or 25,000 Ib RHA in either the double-20 or double-40 parallel parlor resulted in a 10-1 2% drop in CPH. These results show that it is critical to match parlor capac- Milking parlor performance data from time and

motion research' and simulation studiesR has indicated that parlor performance efficiency decreases as a result of: 1) increased parlor size, and/or 2) parlor design (herringbone vs parallel)' 8 Parallel parlors outperformed similarly sized herringbones' 8 Thomas" showed that double-1 6 and double-20 parallel parlors outperformed their herringbone counterparts by about 1 3 CPH. This research also indicated, as shown in Figure 1, that smaller parallel parlors (i.e., double-1 6 and double-20) operated more efficiently than larger parallel parlors (i.e., double-32 and double-40). For example, a double-20 parallel parlor operated over 18% more efficiently than a double-40 parallel.

The primary reason for decreased performance with increased parlor size would be due to the interaction between parlor size and the time required to perform individual parlor tasks. All parlor tasks require a relatively short time to perform. For exam-

ple, it took about 4 seconds to attach a milking machine in a parallel parlor. However, a small percentage of the time it took perhaps 15-20 seconds. The same situation arises for all parlor tasks in that a small percentage of the time they will take much more time than usual. Since parlor tasks are performed sequentially, a task that requires a very long time will delay the performance of subsequent tasks and ultimately increase the overall cycle time for the cows currently in the parlor. This effect is even more detrimental to parlor performance as parlor length increases because a greater number of cows are affected. Plus, the possibility of a task taking a lengthy time increases as the parlor becomes larger simply because there are more opportunities for it to happen within a given milking cycle.

Parallel parlors enjoy a number of advantages over the herringbone. In parallels cows have over 35% less distance to travel to enter the parlor as compared to a herringbone parlor. This shorter distance reduces the first cow entry time by over 4.5 seconds in a double-16 and nearly 6.0 seconds in a double-20. In parallels the time required for milk- ers to walk between stalls during premilking preparation and machine attachment is also less and the average lime to attach machines is generally 1.5 to 2.9 seconds shorter than in herringbones’ 8. Indi- vidually these differences appear small; however, they are additive and thus increase work routine time and decrease parlor operating efficiency in herringbones. These differences in cow entry time and work routine also will allow the same number of

operators to effectively utilize more milking units in a parallel versus herringbone parlor.

Table 2 presents cost estimates in the southeast- ern and southwestern U. S. for construction and equipment for double-20 parallel and herringbone parlors. The difference of $34,000 in cost only represents 6.5% of the totally equipped parlor cost. Using a 15-year planning horizon, 7.5% discount rate, and 34% tax rate, the difference in net parlor returns (NPR) favor the parallel by about $688,950. This economic advantage has little to do with the relatively small advantage the parallel enjoys in initial cost, but is primarily the result of its higher operating efficiency which allows higher cow throughput and thus a larger herd size to be maintained over its entire useful life.

Parlor costs for two double-20 and a single double-40 parallel parlor(s) are presented in Table 2. The difference in initial cost is $22,227 or 2.3% of the total initial cost. If the dairy design was an open corral with shade design typical of the southwestern U. S. the difference in corral costs for smaller pens necessary for the two double-20’s compared to larger pens for a single double-40 would be approximately $60 per corral for extra lanes, fences, water tanks, etc. Table 5 shows the physical (CPH) and economic (NPR) performance for two double- 20 parallels versus a single double-40 parallel. Dif- ferences in total corral costs are included. The advantage of 17% in CPH and 26% in NPR for two double-20’s should be a major consideration for dairy owner/managers planning new parlor facilities or considering renovations of existing parlor facilities.

Conclusions Selecting a milking parlor(s) is a major manage-

ment decision because the choice will determine maximize herd size and impact profitability of the dairy farm for many years. Parlor design and size and management decisions on frequency of milking and pre milking hygiene routine all need to be considered in thisdecision. Future levels of milk production during the expected lifetime of the parlor should be considered but will be of less importance

Economical FeedingAnd Management

Practices For HerdsApproaching 30,000-

Pound RHAs:A Panel Discussion

Panelists:Brad Houston, Price’s Roswell Dairy,

Roswell, NM,

Dennis Lagler, Lagler Dairy,Vancouver, WA

Moderator:Don Bath

Extension Dairy Nutritionist Emeritus,University of California, Davis, CA.


GG enerally speaking, high milk yields percow are associated with greater profitabil-ity of the dairy enterprise. Average milk

production per cow has more than doubled sincethe 1950’s. Many lower producing dairy herds havegone out of business during that period, while themore efficient herds have expanded tremendously.However, not all high producing herds are profitablebecause profitability is dependent on economicalinputs as well as high milk yields. The panelists inthis discussion are dairy managers who run two ofthe highest producing herds in their respective states,Washington and New Mexico. They give their viewson feeding and management practices that result ineconomical milk production in extremely high-pro-ducing herds.

Briefly describe your herd

Houston:Price’s Roswell Farms has been in the Pecos Val-

ley of New Mexico since 1945. We have a grade herdof cows but have concentrated on a good geneticbase. Artificial insemination has been used in our

herd since the arrival of frozen semen. Before that,we collected our own bulls and bred A.I. We are onDHIA official testing and our records are processedat DHI-Provo. Our current DHIA rolling herd aver-age is 23,781 lb. of milk on 1,522 cows. We alsohave about 1,800 calves and heifers on the farm.

Lagler:Our dairy is in Vancouver, WA, just outside of

Portland, OR., 17 miles from Portland InternationalAirport. Although we are 2nd generation on this site,we are fast becoming “urban” farmers. (four lanesof traffic and sidewalks in front of our milking par-lor). Dad and Mom moved from Tillamook, OR, in1955 and Jan and I began buying the farm from themin 1975. We have 535 cows in the herd, about 475milking. We raise all our replacement heifers andsell the bull calves. We have 600 head of youngstock. Currently, our rolling herd average is 25,946lb milk with 814 lb protein.

Do you raise your own heiferreplacements? If so, describe your

calf management system.


Feeding For 30,000 Lbs.

BIRTHColostrum – (1 gallon first 12 hours)Intranasal vaccineiodine Navel – (7% Iodine)Selenium Shot – (1cc)

WEEK 5:IBR BVD PI3 BRSV

WEEK 11:Respiratory Vaccine – (1 shot vaccine)

4 MONTHS:7-Way Clostridial/Hemophilus Somnus

6 MONTHS OR BEFORE:4-Way Virus7-Way Clostridial/Hemophilus Somnus

PRE-BREEDING:(1 month)

IBR BVD P13 BRSV LEPTO 57-Way Clostridial/Hemophilus Somnus

PREG CHECK:Lepto 5

SPRINGERS

Routine Dry Cow Program:Endovac-Bovi 2 Shots7-Way Clostridial/Hemophilus SomnusSelenium Shot (5cc)

FRESH COWS (1-3 weeks)IBR BVD PI3 BRSV

PREGNANCY EXAM:LEPTO 5 – (when pronounced pregnant)

DRY OFF:Reconfirm pregnancyDry Cow TreatmentEndovac-Bovi 2cc IM Dry-off time and 2 weeks laterfirst year; 1 shot following years7-way Clostridial + Hemophilus somnus

1 MONTH PRIOR TO CALVING:Selenium shot – (8cc IM and 2 weeks later)Rotavirus, Coronavirus, E. Coli and Clostridium per-fringens Type C

2 WEEKS PRIOR TO CALVING:IBR BVD PI3 BRSV Second shot of virus, E. Coli and Clostridium

Houston:We maintain a closed herd and raise our own

replacements. Calves are raised in hutches for onemonth and then moved to pens in groups of eight.Calves are fed with bottles; colostrum milk ischecked with a colostrometer for quality. The bestmilk is fed to the youngest calves. We do not feedany mastitis or sick cows’ milk to calves. Calves areweaned at three months. Dehorning is done at threeweeks, and the horn buds are burned with a portablebutane-powered dehorner. An extensive vaccina-tion program is administered to the herd under thesupervision of our veterinarian as outlined on thefacing page.

Lagler:Presently we are starting heifers in hutches, then

move them to group pens. As they get older, theyare placed in another group at a different loca-tion.And finally, regrouped at the other location andreturned to the farm. We need a freestall barn withlockups for better supervision and better condition-ing into top producers. We feed primarily grass silageand alfalfa hay to encourage larger size. Corn silageputs on weight, but not enough size. Presently webreed the heifers to calve at 24 months. In the futurewe want to increase the size and frame of the ani-mal so we can reduce the calving age. If we couldkeep our springing heifers separate from our otherdry cows, we could feed them to grow (and themature cows wouldn’t gain too much weight.)

We need better heifer facilities to take better careof heifers.

What are the factors that you feel areimportant in your breeding program?

Houston:I feel strongly that a large cow is needed to han-

dle the nutrients required for high milk production.For the same reason, I generally use calving easebulls that are eights or nines. All cows and heifersare evaluated for sire recommendations. July 1994guidelines are +1200-TPI; +300 protein $; +80 lb.protein; +1.5 type; and +1.00 udders; +.01 legs;

+1.00 body depth; +1.5 dairy composition. I makea few exceptions to these guidelines so that I can getenough bulls. We breed first choice twice, secondchoice once and then we go to young sires. Heifersare bred to calve at 24 months.

Lagler:We select bulls according to minimum standards

for milk, cheese yield, and type. Obviously there aresome cows where you might stress one criteria moreand another less. We want to do some ET work togenetically improve our herds protein componentin the milk.

We AI all heifers, spending about $22-$25 perstraw. We get the best return for our AI dollar byspending more on the heifers to improve protein,udders, feet, legs, and capacity.

Describe your cow grouping system,including dry cows.

Houston:Our milking cows are grouped into warm-up cor-

rals, breeding corrals, and pregnant cow corrals. Freshcows and hand milk cows are milked in a separatefacility. Cows are milked 2X daily. Cows are pre-dipped and post-dipped. Fresh cows’ udders areflamed before going on milk strings. Periodically weflame all cows udders as they leave the milk barn. Drycows are grouped into far-off drys and close-up drys.

Lagler:We milk three times a day. Our milk cows are

divided into 3 herds and a hospital string. Each herdhas its own separate rations. They are fed a TotalMixed Ration (TMR) 3 times a day, each followed byone or two feedings of alfalfa hay. The dry cows aredivided into 3 groups. The just-dried cows are fedoat hay with a mineral supplement. The intermedi-ate-dry cows are fed silage and 4# grain with a min-eral supplement. The close-up cows are fed 10#milking ration and free choice oat hay. Currently wehave heifers in with the intermediate dry group. Wewould like to keep the heifers separate and feed moreroughage to the dry cows in the form of oat hay.


Most of our mastitis problems come from ourfreshening cows. We need to strengthen the careand feeding of our dry cows.

Do you employ a nutrition consultant?

Houston:We work very closely with our nutritionist. Dur-

ing his visits, he and I visually look at all the cat-tle. He samples any feedstuffs that need to be ana-lyzed. The same lab is used for all nutritional work.

Lagler:We test our feeds and a feed consultant (Dr.

Amos Zook of Loper Systems) helps us with ourration.

What is fed to the various cowgroups? How do you monitor theamounts being fed to each group?

Houston:We have rations designed for far-off drys, close-

up drys, fresh cows, warm- ups, breeding andpregnant categories. Oat hay is fed to the drycows every other day with a mixture of alfalfa hay,corn silage and cotton burrs. High phosphorus min-eral and salt are fed to the dry cows free choice.Ingredient composition of the rations are shown inthe table.

The close-ups are fed 10 pounds per cow of thedairy cow mix in addition to their roughage. Freshcows are fed 30 lbs. of the dairy mix. Warm-up cowsare fed 39 lbs. of the dairy mix. The cows stay in thewarm-up corrals for 30 to 45 days. The breedinggroup is fed 46 lbs. of the dairy mix. The proteinlevel is 16.74% and the crude fiber is 14.5%, bothon a 90% dry matter basis. Their present total con-sumption is 64 lbs. Pregnant cows are fed 39 lbs. ofthe dairy mix. Total consumption is 55 lbs. per cow.

We have a ration program on our computer. Cor-ral numbers are updated every day and a new rationis printed for the feeder. We monitor feed invento-ries very closely. As you know, cows are creaturesof habit so we try to feed them similar ingredientsevery day at the same time.

At present, we are not feeding a total mixed ration(TMR). Alfalfa hay is fed one hour before the grain-silage mix in the mornings at 6 AM. The grain- silagemix is fed at 7 AM, 3 PM, 8 PM and 2 AM. Ourfeeder puts out the mixed feed at 7 AM and 3 PM,and loads the two night loads. The barn foremandoes the feeding at night. Thirteen pounds of rolledcorn and rolled milo on a 50- 50 basis are fed in thebarn during the milking process.

Separate loads of alfalfa haylage, corn silage andalfalfa hay are fed at regular intervals during the day.The ration is pushed up to the mangers every sixhours. Oat hay is fed to dry cows every other day.This works well in our feeding logistics.

Protein feeds currently used are cottonseed meal,dried distiller’s grain and a blood meal, animal fatpremix with hominy or wheat midds as a carrier foreasier handling capabilities. Our molasses mix is a41-1 mix. We feed six pounds of whole cottonseedper day to the milk cows. I usually feed milo hominyinstead of corn hominy because of the price spread.Other commodities used are cottonseed burrs, beet



Ingredient Composition Of Price’ s Roswell Rations

dairy warm-up highs preg.ingredients cow mix ration ration ration

C/S meal sol 3.50whole cottonseed 6.50distillers grain 2.75beet pulp 3.75grain screen pellet 1.00hominy 4.00blood meal mix 4.00mineral mix 1.70alkaten .30cotton burrs 2.0041CP-1P molasses 1.00corn silage 14.00 10.00 10.00 10.00alfalfa hay blend 4.00 2.00 4.00 4.00oat hay 1.00dairy cow mix 39.00 49.50 39.00alfalfa haylage 13.50 14.00 13.5050% corn-50% milo 13.00 13.00 13.00TOTAL 49.50 77.50 90.50 79.50lbs. air dry intake 39.08 53.04 63.51 55.04lbs. grain/cow/day 28.35 35.34 41.35 35.34

cost ($/cow/day) $2.90 $3.62 $4.36 $3.74

pulp, bufferite, and calcium. Heifer mineral withmonensin is fed to heifers from three months through17 months. It is very difficult to get enough fiber ina high energy milk cow ration.

Lagler:Dry matter intake is the key to high production.

We constantly strive to improve the quality of homegrown roughages. We intend to try mixing alfalfawith grasses instead of clovers to achieve high pro-tein and tonnages in later cuttings. Our Total MixedRation is based on home grown silage. Besidesground corn, we use a lot of by products: whole cot-ton seed, bakery waste, beet pulp pellets, canola orsoybean meal (soy is more dense, but also more $$),mill run (source of phosphorous), and a vitamin andmineral package. A typical ration for the high cowherd in “as-fed pounds” would be:

5# whole cottonseed5# canola7# ground corn3# bakery waste6# beet pulp pellets3.75# wheat mill run1.5# soybean meal7# liquid brewers yeast1.33# lactating mineral and sodium bicarbonate18.66# grass silage25# corn silage16.25# alfalfa hay in the mix4# loose hay in addition to the TMR

We add liquid yeast to the total ration to keep themoisture at 50%. When the mix is wet, we back outthe liquid yeast.

Total cost per day of high cow ration is $4.20/cow/day giving and average of 101# of milk. Thewhole milking herd cost is $3.60/cow/day currentlyaveraging 84# of milk or $4.29 per CWT of milk.

Do you grow or buy your forages?What quality standards do you

require for your forages?

Houston:The alfalfa hay fed to the milk cows is generally

purchased locally from three producers. Each pro-ducer’s hay is stacked in barns and kept separatefrom the other producer’s hay. I try to purchase alfalfahay that is 21% protein on a 100% dry matter basis.The acid detergent fiber should be 31% or less. I wantthe stems to be soft and the hay to be free of foreignmaterial and bright green in color. Moisture contentof 13 to 18 % is necessary for storage.

We grow our own alfalfa haylage. It is cut at veryearly bloom. It is stored in a pit, inoculated, packedproperly and covered with 6 ml plastic. Our aver-age shrinkage is 8%.

Corn silage is contracted from local farmers. Weinsist on grain varieties of corn that will produce highquality roughage. The farmers are paid on a slidingscale with 72% moisture being the base.

Lagler:We purchase all the alfalfa hay we feed the milk-

ing cows from eastern WA and OR. We test the hayfor moisture, protein, acid detergent fiber, neutraldetergent fiber and lignin. On a dry matter basis, wewant 22% protein, 25- 28% ADF, below 40% NDF,and below y.5% lignin. We strive for high intake,high density (not hot) and high digestibility.

We raise orchard grass on the land we spreadheavily with liquid manure. On the land we grazeand chop for silage, we plant annual and perennialtetraploid rye grasses with white clovers. We receivean average of 44” rainfall in our area. Because ofour climate, we have gone to the Ag Bag system forsilage storage. This way we are able to harvest thecrop when weather permits and the crop is in earlymaturity. The first two cuttings are for silage. On theirrigated land we make two more cuttings into hay,on the dry ground we get one cutting of hay. Cut-ting the grasses for hay and silage at the correctmaturity is one of the most important managementpractices we try to follow.

The years when we make good quality silage, itis much easier to get high milk production and beprofitable. The bagging system also allows us to keepour higher quality feed for the milk cows and divert


high fiber feed to the heifers. Feed must be fertilizedcorrectly, be free of weeds and cut at correct matu-rity for highest nutrient quality and digestibility.

Do you have any final comments:Houston:

Our motto is, “Our cows are not contented. Theyare striving to do better.”

Lagler:Our overall goal is high production at economi-

cal feed cost based on home grown forages. Keepmilk quality up and protein up in milk so we con-tinue to receive the highest price for our milk.

At the present time, our co-op pays a premiumand they do not want milk from BST-treated cows.When given the OK by our co-op, we would con-sider using BST on the DNB and tail-enders as amanagement tool.



notes

Feeding To MakeMoney: ManagingNutrients In The

Total HerdBy Charles J. Sniffen

President,W. H. Miner Agricultural Research Institute

P.O. Box 90, Chazy, NY 12921518-846-7121

fax 518-846-8445


eeding to make money takes on many shapes, ent balance on the farm. It is this latter point that We can spend a lot of time tal king about least prompted me to place manure management in sec- F cost or maximum profit ration formulation, ond position. We need to carefully integrate our

feed purchasing and growing strategies. We can dis- nutrient input on the farm with the nutrients leaving CUSS the strategies in feeding the various groups of the farm. A price needs to be placed on the removal animals on the farm. We can make quantitative of N, P and K from the farm in a form other than points about the importanceof analyzing feeds. We milk and animal. can discuss the optimum strategies for manure man- Growing crops needs to be considered as a feed agement. Outlines can be made of the daily feed- procurement activity. If this is a part of the feed oper- ing management strategies. Each of these are impor- ation you need to ask whether it is making you tant and a significant amount could be written about money. Can you buy the quality forages/grains for each of them. The goal is to make a good return on less money than it costs you to grow them? If you investment. In order to accomplish this it is neces- can, will the quality be as consistent as that which sary that we integrate each of these areas into a sys- you can produce? If you are to purchase forages tem. It is the system approach that we will use in what will this do to your farm nutrient balance? If our discussion in this paper. the decision is to produce forage/feeds on your farm

Too frequently on farms we spend excessive time then how can you produce them most profitably? on the area that we feel most comfortable with or You should know exactly what your per-acre costs like most. Some of us would rather spend time with are, including costs such as taxes, machinery depre the milking cows, others with the replacements and ciation, storage costs and depreciation, inventory still others with the crops. The truth is we need to shrinkage, and nutrient variability from year to year. spend enough time on each of the areas in order to Finally, it is important to know what your real yields make the area profitable. are per acre. This means weighing the crops as they

I think that it is important that you divide your come off the fields, and it is suggested that scales be feeding system into profit areas. I would suggest installed.This means knowing the exact acreage that some of the following divisions; you may have you are growing your crops on. Many of us do not more: have exact measurement of the acreages that are

I can’t overemphasize the importance of quality forage for optimum performance in your herd. Quality has may facets. The most obvious one is the nutrient content of the forage. It is critical that the appropriate forage with the correct nutrient content be available for all cattle at all times. This means routine analysis of the feeds. The most important routine analysis is the moisture level of the ensiled or wet feeds, I f they are to be used in a TMR. In Fin- land and the U.K. they also measure the digestible dry matter, using enzymes. This practice is also used in Japan. This allows them to feed more forage than we do. We have not adopted the approach yet, partly because we are using legumes and have found that using enzymes to predict the energy Val-

ues of forages is not accurate enough. We need to

Feed Procurement being cropped. Manure management Animal grouping and flow Ration formulation Feeding management

These divisions represent areas that can have a significant impact on cash flow and profitability. This list does not include labor management; it is implicit and the costs are real. It is essential that you understand that each of these areas are not isolated, but are interdependent. It is this last point that many times is not considered when making management decisions. This can become exceedingly painful when capitol expenditures are involved.

Feed Procurement When we discuss feed procurement we need to

now consider nutrient flow on the farm and nutri-

put much emphasis on this in the future i f we are going to increase profitability. It is important that we measure the protein and carbohydrate fractions. Equally important are the macro and trace elements. We need to know more about the availability of the minerals in the feeds to the rumen and to the cow.

The feed storage system needs to be designed so that it will be possible to access quality forages at all times. The system needs to be arranged so that the time to feed is minimized and accuracy will be assured. Quality also means that the particle size is correct, the acid or NH3 levels are not excessive in the silages. If the milk is to be used primarily for manufacture of soft cheeses then clostridial spore contamination of the silage becomes a concern. Feeds need to be f r e e from molds and yeasts. Aer- obic stability is of great importance for silages and the amount fed out each day needs to be adequate to ensure fresh feed.

The purchase of feeds takes on several dimensions. First, the feeds should be purchased based on economic considerations. These economic considerations are the following:

Price Variability of price

Availability of feedstuff Grouping Variability of nutrients

The other considerations are quantities that you need to purchase to get a good price and the inventory turnover. It may not be wise to buy a quantity of an ingredient that will turn over slowly, especially if that ingredient has a poor shelf life. Remember, this is money that is tied up for a period of time that may be uneconomical when compared to buying it as a percent of a supplement that will turn over more frequently.

It has been my personal observation on many farms that there are inventories of minerals/vitamins and other feed additives on the farm that do not meet the needs of the herd and out of date. Careful planning is needed to control these inventories.

Manure Management Nutrient balance is becoming an important con-

sideration in the purchase of feeds. If you are pur-

chasing excess amounts of N, P and K from feeds that cause nutrient balance problems on your farm then you need to reconsider the purchase of that feed. For example, the latest problem is with K. We are finding that high-K rations is the primary cause of milk fever. We are, with manure lagoons being highly efficient at recovering the K excreted by the cow in the urine. This is being spread on the fields and the forage plants are taking up the K in luxury consumption. It is becoming a challengeto balance against high K forages. Anionic salts have helped. However, the long term solution is to reduce the amount of K that we bring on the farm.

Feeding excess N is not only wasteful, but it will also have a negative effect on animal performance, particularly reproductive performance. In hot areas, especially where humidity is a problem, excess N intake can increase the animal's heat production and also water intake. This will cause a change in the animal's intake behavior and lead to metabolic upset. This problem can be compounded i f water intake is restricted in any way. It will not be long before there will be an additional cost that will need to be input into our ration programs to economically assess the cost of manure disposal.

The concept in the grouping of animals is to create groups that are as uniform as possible in size, age, productivity and stage of lactation and/or gestation. This is advantageous from a nutritional point of view. It is also will reduce the feed costs per animal per day. For example, if we are feeding one lactation group we will feed for the high producing animals in thegroup, i.e. the cows between freshening and peak. We are overfeeding the cows in mid to late lactation. Another advantage to grouping is being able to feed special supplements that are high cost for short periods of time. This is especially important during the last 3 weeks before calving and the first 4 weeks after calving.

Grouping should be a dynamic process. The system should be designed to minimize labor and to maximize taking advantage of the physiological state of the animal. For example, we need to espe-

cially focus on the replacement between weaning defined the different physiological groups on the and puberty, the late gestation cow in the last 3 farm. weeks before calving, and the fresh cow. There is Please understand that physiological and physi- an optimum blend, depending on things such as cal groups do necessarily equate. You will, in all herd size, holding area and parlor size, calvings per probability, have less groups. However you need to, week, distribution of lactation numbers for the for ration formulation purposes, adjust your rations weekly calvings, and season of the year. to accommodate the differences in intake and

Animal numbers in a pen/string need to be gov- requirements for the different groups physiological erned by feed/water bunk space and resting space. groups that you put together. The obvious one being The rations that are formulated for the group will putting springing heifers in with the dry cow groups. depend on the lactation number or age, body They have a growth requirement and eat less. weight, days in milk, milk volume and composition Ration Formulation and daily gain. Factors such as temperature in the Most nutritional consultants today are using a pen need to be considered when formulating the least cost ration program. If you are buying supple- diet. It is important to realize that the ration for a ments from a feed manufacturer they usually will be designated pen can change frequently depending using a least cost program to formulate rations. There on the composition of the pen. are a number of least cost programs available to pro-

The herd, contrary to popular belief, also has ducers that are good programs. There is only one replacements and dry cows. Further, the replace- maximum profit program that is available on the ments are not a homogeneous group but at least 6 market. This is based on the original program devel- groups with distinct differences in nutrient require- oped at the University of California and is now avail- ments. The dry cows, defined able through Tri Logic. here as those animals that have I am most familiar with gone through one lactation or Spartan, a program devel- more, have at least 2 groups oped at Michigan State Uni- and some would argue 3 or 4. versity, and the University of If we think of the different Pennsylvania version of the groups of animals on the farm CornelI Net Carbohydrate not as physical groups in the Amino Acid model, both of sense of pens or strings, but as which have LPs in them. I physiological groups with will restrict my comments unique nutrient, behavioral and about formulation to those management requirements, two programs. then we can better physically I Iike to use a LP in the for- group the animals and formu- mulation of rations for farms. late rations for them that will It forces me to be more logi- maximize performance, at high cal. We need to ask many efficiency and at maximum re- questions about the herd, turns. We need to first define groups of cattle, feed inven- the physiological groups on the tory, the environmental re- farm and then provide some strictions and the any labor guidelines for the management restrictions that may be im- of the groups so that we can posed (i.e. feeding another better feed the herd. Below are time each day). Kalter and

Skidmore developed, with support from Elanco, a Expert System model called DAIRYPERT. This model was discussed in a Cornell Agricultural Economics publication in 1991. The model was to have been released by Elanco for use in the field in relation to the management of herds receiving bST. It never was released. I was disappointed because it represented a significant step forward in identifying problems on the farm. The model asked the producer many questions about the farm system. Much emphasis is placed on the physical facilities. Cow comfort and bunk space for feed and water are emphasized. If these are inadequate the program will warn the user of a problem. For example, if the feed bunk space is restricted to less than 2' per cow, it is warm, there is secondary fermentation in the forages, the facilities are poorly ventilated and the producer feeds once per day, there will be a warning given. The program will provide guidelines for change. The change could involve feeding management, change in ingredients (the Cornell model is built into the model to assess the interaction of the environment and the ration) led and/or facilities. This is a systems approach to ration management. This is the approach that we need to take in the future. For now the LP allows me to make these type of decisions in an organized manner.

Will Hoover, West Virginia, has placed much emphasis on carbohydrate nutrition. This emphasis is correct. The dairy animal is a ruminant. We must formulate rations to maximize rumen function. This makes sense from an economic viewpoint and in terms of nutrient management. Hoover's group has developed a fermentable carbohydrate system. He has conducted research that demonstrates the value of highly fermentable fiber in feeds. He calls this the fill

system. Rapidly digested fiber will reduce the fill effect of the fiber more quickly allowing the cow to eat more. This concept is supported by the work of Allen of Michigan State University who has determined that there can be large differences in the digestibility of fiber of different corn silage varieties.

The second component of the carbohydrate system is the non fiber carbohydrate(NFC). This is a calculated number that represents the sugars, starches VFA, pectins and glucans. The sugars and starches are the major components that have the greatest impact on rumen function. Hoover has developed a large data base on the sugar/starch content of feedstuffs. He has also measured the fermentability of the sugar/starches in the rumen. From this he has developed some preliminary recommendations for feeding the early lactation cow. He does not use the net energy system. He feels that the cattle will perform if we balance the carbohydrate and protein fractions. I would go one step further in the formulation. I think that many times becauseof feed inventory and environmental considerations we do not have the right combination of fermentable ingredients. We can include fat as a energy source. This is a good management tool.

I have been using Spartan to do routine balancing of these components. Spartan has a column for starch and fermentable starch. There are 4 columns

that can be added and I have added fermentable fiber as one of them. In Tables 2 and 3 can be found examples of the approach used in formulating with an LP. In Table 2 we define the nutrient requirements with modifications for the environment that surrounds the group.

In Table 3 we can constrain the feeds as defined by feed inventory or quality constraints. Placing a price on the feed, either what it costs delivered or what it costs to produce it.

There have been many consultants who have adopted this concept on carbohydrates and proteins and I believe are well satisfied. There are many people now using the Net Carbohydrate model. The

of lipids that we feed to dairy cows. Too much unsaturated fat from vegetable sources has a negative effect on rumen function. This is especially true if the cow eats a significant amount of the unsaturated fat at once. A mixture of saturated and unsaturated fats is best. If rumen bypass fats are being fed it is important to know the digestibility of the fat. It appears that some fats that are high in Stearic fatty acid have a lower digestibility in the small intestine.

Since the publication of the dairy NRC, formulating for protein fractions has become pretty well accepted. The major flaw in the system is still a lack of a good laboratory analysis system that is acceptable to everyone. In the Northeast we have been

measuring protein solu- bility and acid detergent insoluble protein for many years. We feel that this gives us an estimate of the rapidly rumen degraded protein and the u n ava i I ab le protein. We have been using the S. Griseus enzyme to measure degradability or measuring the protein insoluble in neutral detergent

combined with rates of digestion to measure the bypass(Cornell Model). We need to reach agreement on methods. We have been reasonably satisfied with the above methods.

Ration formulation for the degradable and soluble protein is extremely important for all groups of animals on the farm. If these are balanced properly the carbohydrate fermentability will be enhanced. The work of Hoover and field experience strongly argues for providing part of the degradable protein from solvent extracted soy. This provides the pep- tides and rumen degradable amino acids needed to enhance starch and fiber digestion.

Once the rumen is optimized then it is necessary to provide a quality bypass protein. It is suggested that a combination of corn gluten meal, blood meal and a little fish meal makes an excellent supplement.

above concepts are in the model in a more sophisticated form. I have found that I can use the concepts that are in DAIRYPERT on environment and management analysis to help me set the minimum and maximums on starch and fiber fermentability to formulate rations that perform. We need much more work on this. At this point I would be working closely with your nutritionist to evaluate the rations for these carbohydrate and protein fractions.

The use of lipids in rations has now become an excellent management tool. For high producing herds it is recognized, given the variable environment that surrounds the cows and the variability of our forage quality (fiber digestibility being the major one) and grain quality, that we often need a high energy source that is consistent. Lipids provide that source of energy. We need to be careful in the type

This will provide the right amount of methionine, lysine, isoleucine and possibly arginine needed for optimum production. Our recent research has emphasized the importance of amino acid nutrition for the dry cow and fresh cow. Research is suggesting that we need to pay attention to the protein quality for the replacement from birth through at least puberty. After this the replacement should be able to obtain enough amino acid from microbial flow to the small intestine.

Mineral and vitamin nutrition of the dairy animal can be the most important part of the nutrition program. It is often forgotten or we make sure that the Ca and P are adequate and do not look much further. In fact we need to constantly monitor the mineral and vitamin nutrition of the total herd. The requirements are significantly different among the different groups of dairy animals on the farm. We need to pay particular attention to the trace minerals and vitamins. It is easy to assume that the balances are correct but frequently the balances change with changes in the forages.

Water is frequently overlooked. The water needs to be moderate in its mineral content. Data would suggest that the pH of the water should be near 7.0. If the water is over 8.0 or below 6.0, there can be an intake problem. Bacterial contamination, especially coliform, should be minimal or non existent. The water should be free of organic matter contamination. This means that the water tanks need to be cleaned frequently. We use tip-type waterers that are on a pivot. These are very easy to dump and clean. Waterers are an excellent place for stray volt- age. This needs to be checked carefully by someone skilled in the area. The available space for cattle to drink is a function of productivity level and environmental temperature. In too many barns there is inadequate "bunk" space for cows to drink. I saw at a farm in Alberta, Canada where there was a flow- ing water trough for each side of the parlor. I was in a parallel parlor in Japan where there was a water trough on the front of the stalls in the parlor. Both of these producers were very satisfied with the results.

Feeding Management

We can balance the most sophisticated rations in the world with the most sophisticated grouping system and the animals will not perform. HOW we feed what we have formulated is the difference between success and failure in making money form feeding your herd. You need to have some monitoring tools in place. Historically, the use of DHI has been a tremendous tool for management. Today it still is an excellent tool. However, due to herd size and the dollars involved we need more frequent measurements. The use of electronic milk measurement, cow ID and microcomputers have provided us with some excellent additional tools. In addition we need to use keen observation on dry matter intake amounts and change, body condition score and change, manure condition score and change, and change in milk volume and composition over the lactation. With this management information you will be able to make intelligent changes in rations and daily feeding strategies.

There are some additional measurements that might be helpful in the future. In Sweden and Fin- land they have been using milk urea and milk a c e tone as a routine management tool. The combination of these two measurements provide information on the cow's efficiency in the use of protein and energy status. The concept of measuring "signature" metabolites in milk is not new. We discussed this several years ago with people from Kodak. If unique metabolic products of metabolism can be identified in milk and measured cowside and/or through DHI, it can help in making management decisions. To date in addition to milk fat and protein we have available the potential of acetone, progesterone, urea, non protein nitrogen (urea is a part of ) and citric acid. We do not know much about citric acid. This information is available when the milk ureas are run on the latest instrumentation from Foss Elec- tric. Research needs to be done in his area.

We need to apply the principles discussed above to the whole herd. We need to start with the replacements. We need to plan on replacements calving at 21-23 months of age at BO-85% of mature frame size. This will result in a significant percentage of the first calf heifers peaking over 100 Ibs. of milk if

they are Holsteins. This, in reality, becomes the most important part of your nutrition program in the herd. This will result in you also able to feed a higher proportion of forage to the total herd, which increase your profitability. In that you will be able to assess the quality of the animals in the first lactation you will be able to cull more intelligently on production. The lategestation animal or dry cow nutrition needs intensive management. All of the feeds need to be analyzed for these groups. You will need high quality bypass protein supplements and you will need to balance the minerals and vitamins carefully. The key is to make absolutely sure that what you are balancing for they are eating. Feeding hay on the side will not work. Chop it and incorporate it into the ration. We are also finding that we need to balance the ration protein for 13-1 5% C.P. with 25-28% of the protein being soluble for the close-up dry group. The first 4 weeks post partum is critical. The cows

are not eating at capacity so there is a need for a high ration density with a carefully balanced carbohydrate mix.

Good feeding and environmental management is a must during this period. If the cows are sharp and aggressive after the first 4 weeks then the rest of the lactation will fall in place.

Summary Feeding the high producing herd needs a total

integrated approach. If you do not want to do this yourself then identify a nutritionist that is willing to look at the total picture. Have the nutritionist sit down with your veterinarian, crops specialist (If you are growing forages) and key herd people to discuss the total herd. nutrition program. Identify the weak links and prioritize the short term and long term goals for the herd. You will find that the return over feed costs will begin to improve.

ManagementStrategies ForTMR Feeding

SystemsBy Dr. Jim Spain,

Assistant Professor and Extension SpecialistAnimal Sciences Research CenterUniversity of Missouri-Columbia

S134 Animal Science Research CenterColumbia, MO 65211

314-882-6452fax 314-882-6827


DD uring the last 3 decades, average herd sizeof U.S. dairy farms has increased. Over thesame period of time, production per cow

and level of concentrates fed per day have alsoincreased. In 1969, A.H. Rakes suggested thesechanges were increasing the need for specializationand automation of the feeding system, and as a resultof these changes, new feeding systems have beendeveloped. Coppock and coauthors, in 1981, re-viewed the ongoing shift from feeding individualingredients in multiple locations to feeding com-plete rations. The reasons for these changes werethe same as those discussed by Rakes. As dairy farmmanagers adopt, adapt, and manage total mixedrations, there are several key points that can influ-ence the success of the feeding system in meetingthe goals of the nutrition management program. Thefocus of this paper is the evaluation of critical deci-sions or control points in successfully managing totalmixed ration (TMR) feeding systems.

Grouping DecisionsGrouping decision is the first decision in manag-

ing the TMR system. Simply put, which cowsare assigned to which groups and what willthese cows be fed? Some fixed factors such aslot size, stalls per lot, and size of milking par-lor/holding pen will influence feeding groupsize. But how cows should be assigned to lotsis an important management consideration.

Nutritional requirements, age, body con-dition, reproductive status, and health, havebeen and are used successfully on commer-cial farms to assign cows to groups (McCul-lough). Grouping by age for example, allowsproducers to limit social diversity and rangeof dominance within a group. Open (non-pregnant) cows in a single group can improveefficiency of reproductive management (ie.,estrus detection program focused on fewergroups). Some herds use separate groups tomanage sick cows. By managing this groupseparately, managers reduce exposure ofhealthy cows to disease and allow cowstreated with antibiotics to be milked last or in

a separate parlor. This management practiceimproves residue avoidance programs. However, theoverwhelming conclusion of research in this areaindicates grouping by nutritional requirements is thebest basis for grouping cows into feeding groups.

The basis of any diet formulation is the accurateprediction of dry matter intake (DMI). Kertz and oth-ers summarized results of feeding trials conductedover a six year period. These researchers reporteddry matter intake was better estimated if days in milkwas included in the prediction equation. In addi-tion, prediction of dry matter intake was most accu-rate if intake was predicted for each week from calv-ing to 42 days in milk. After 42 days postpartum,predicted dry matter intake was improved if calcu-lated for weeks 6 to 8, 9 to 13, and 14 to 20 of lac-tation. Another important observation was the dif-ference in feed intake of first lactation cows com-pared to later lactation animals. These results definethe importance of measuring and monitoring drymatter intake across groups. Therefore, TMR systemsshould be based on ration mixers equipped with


Management Strategies For TMR Feeding Systems

Table 1: The economic benefits of grouping strategies asinfluenced by level of milk production.

Two Group Scenario

Grouping Strategy Level of Production per Cow(lbs/cow/year) 17,600 19,800 22,000

($ per cow per year)Nutrient Concentration 1,144 1,301 1,531Nutr. Conc./NDF intake 1,144 1,304 1,538Days in Milk 1,137 1,289 1,519DHIA Test Day Milk 1,100 1,249 1,477Test Day FCM 1,126 1,279 1,507

Three Group Scenario

Grouping Strategy Level of Production per Cow(lbs/cow/year) 17,600 19,800 22,000

($ per cow per year)Nutrient Concentration 1,164 1,333 1,570Nutr. Conc./NDF intake 1,166 1,338 1,579Days in Milk 1,166 1,310 1,542DHIA Test Day Milk 1,107 1,275 1,494Test Day FCM 1,133 1,295 1,524

(Adapted from Williams and Oltenocu; J. Dairy Sci. 75:155 (1992).

accurate scale. Accurate dry matter intakemeasurement should then be used to for-mulate group diets. This is critical in deter-mining what nutrient density is necessarygiven the DMI. But, which cows go inwhich group?

Grouping StrategiesSeveral strategies have been proposed

for production grouping of dairy cows. In aseries of studies conducted at Virginia Tech,McGilliard and others evaluated differentmethods to group cows. Grouping criteriaevaluated included CP percentage and Mcal netenergy per lb expected dry matter intake (cluster) ver-sus test day milk, fat corrected milk, (FCM) and FCMper unit metabolic body weight (defined as dairymerit). Over 100,000 test day records from 80 Vir-ginia DHIA Holstein herds were used to allocate indi-vidual cows to groups. Cows were grouped into twogroups per herd each month. Clustering cowsgrouped 25, 22, and 15% of cows in different groupscompared to test day, FCM and dairy merit groupingstrategies. Nutrient clustering decreased the variationwithin groups compared to other criteria evaluated.Schucker and others (1988) conducted a field studyto investigate nutrient requirement grouping of dairycows on commercial farms. Nutrient clustering ofcows into feeding groups was found to be more accu-rate than test day milk production only.

Williams and Oltenacu, using a dairy herd pro-duction computer model, evaluated economics ofgrouping criteria. Several criteria for grouping werecompared for a theoretical 100-cow herd with threelevels of potential milk production per lactation (305d; 17,600, 19,800, and 22,200 lb). These investi-gators reported required energy and crude proteinper lb of predicted dry matter intake or per lb of esti-mated neutral detergent intake capacity supportedhighest milk production and highest income overfeed cost per cow. (See Table 1).

Another decision that must be made is the group-ing and movement of cows to and from feedinggroups. Spahr and colleagues evaluated a groupingstrategy program based on 3.5% FCM productionas a percentage of body weight between 42 and 56

days postpartum. This method was most sensitive inidentifying cows with low potential milk produc-tion. The authors reported difficulty in distinguish-ing between cows with medium or high potential.Results were improved by grouping primiparouscows separately from older cows. Potential prob-lems with allocating cows to production group maybe caused by early postpartum health problems(metabolic or mastitis) that would lower estimatedpotential. Body weight is also an important variablethat would need to be included.

Lead FactorsAnother critical point is movement of cows to dif-

ferent groups and how close the diets comparebetween groups. Spahr and others noted movingcows from high to medium TMR tended to reducemilk production but not FCM when grouping cowsbased on lactation potential. These results point outthe importance of properly balancing TMR for thegroup being fed. Stallings and McGilliard evaluatedmethods of estimating lead factors for the formula-tion of TMRs for production groups. Their study indi-cated that as the group became more similar in milkproduction (less variation within the productiongroup), the lead factor required was reduced. Theresults indicate that feed costs can be potentially re-duced due to less overfeeding of low producers inthe group. In addition, higher producing cows mightbetter realize production potential. (See Table 2).

One-group TMR feeding has been used by dairyfarm managers. Howard has described advantagesand disadvantages of one group TMR. However,while one group TMR may have merits for small to


Table 2. Comparison of milk production and lead factors forcows by percent of cows in each group.

High Middle Low% Cows per Group (Milk/LF) (Milk/LF) (Milk/LF)

100:0 45.3/1.3 ..../.... ..../....50:50 56.3/1.17 ..../.... 34.1/1.22

33:33:33 61.4/1.14 44.7/1.08 30.6/1.2125:50:25 64.2/1.12 44.7/1.13 28.2/1.2050:25:25 56.8/1.17 40.0/1.07 28.2/1.20

(Adapted from Stallings and McGilliard; J. Dairy Sci. 67:902 (1984)

average size dairy operations, large operations canachieve obvious economic benefits by productiongrouping the herd. Advantages of grouping dairycattle include:

1). More accurate ration formulation based onproduction,

2). With increased accuracy of ration formula-tion, production efficiency and profitability can beimproved,

3). Special groups of cows can be better man-aged. For example, first lactation cows can beplaced in groups with reduced competition by older,more dominant cows for feedbunk space.

4). Forages may be allocated and matched to pro-duction group based on quality of forage and levelof production potential.

Feed ManagementWhen discussing feed quality, forage quality is

usually the topic discussed for dairy cattle diets. Itis important, however, that all feeds be closely mon-itored for changes in nutrient composition. For TMRmanagement, the discussion is better focused onfactors that influence accuracy of the diet beingmixed and delivered. One factor often overlookedbut a major influencer of TMR management is drymatter content of ensiled forages. Workers at PennState reported that increased uncertainty in forageDM affected the accuracy of protein and NDF of theTMR mix. Linn recommended ensiled and/or wetfeeds (i.e., wet brewers grains) be monitored weeklyto prevent large fluctuations in diets presented tocows in the bunk. Rainfall can also influence DMof ensiled forages being fed and the accuracy of dietmixing. Equal attention should be placed on mon-itoring DM of the TMR diet being offered in thebunk. Monitoring DM and amounts fed per groupcan be used to monitor dry matter intake (DMI) ofgroups. Dry matter intake is a critical component ofthe feeding systems management. Remember, if youdon’t measure it, you can’t manage it.

In addition to the influence of DM of wet feedson nutrient content of the mixed ration, dry matterof the total diet might influence DMI. Lahr and co-workers reported diets less than 50% dry matter mayreduce feed intake by cows. However, Robinson

and colleagues reported no differences in DMI ofdiets ranging from 35-65% DM. These studies dif-fered in how diet DM was manipulated. Lahr’s studyrelied on replacement of alfalfa silage with alfalfahay. In contrast, Robinson’s experiment used con-centrates and silages soaked in water. The optimaldry matter content of the TMR is the level that opti-mizes DMI by the herd. Close monitoring of drymatter is important in monitory DMI by groups.

To measure DM, an on farm method that providesresults accurately measured and easily attained.Oetzel et al. compared four methods of evaluatingDM of feeds. The microwave proved most accuratebut requires the most time and careful monitoring.The Koster Moisture Tester tended to over estimateDM of feeds but was comparable to microwaving.An electronic moisture tester was also evaluated andfound to be comparable to the DM measurementsmade using the (time) and Koster Microwave oven(smelly house with unhappy spouse). While no sys-tem of measuring dry matter content of ingredientsand mixed rations is perfect, it is important for farmmanagement to be active in managing this impor-tant variable.

Forage Fiber Source ConsiderationsOne goal of the TMR system is to limit “selective

intake” of individual dietary ingredients. In tradi-tional feeding systems, cows were fed concentratesseparately from forages with dry hay and ensiled for-ages fed in multiple locations. As a result, cows hadfreedom to select and consume an unbalancedand/or unhealthy diet. The management goal of theTMR is to blend all dietary ingredients into a singlediet including the effective fiber source. Historically,long, dry hay is fed as a free-choice supplement.Beauchemin and Buchanan-Smith reported theinclusion of long dry hay in the TMR increased milkproduction over 3 lbs per cow per day. In addition,cows consuming hay had meals of longer duration,and increased chews/minute during meals. Cowsconsuming long hay also spent more time ruminat-ing and chewing. Increased chewing time tendedto improve rumen pH by reducing time pH wasbelow 6.0. While not statistically significant, thisshift in rumen pH reflects better natural buffering of



the rumen. This result would be expected to reduceoff-feed problems and health problems (ie., acido-sis, laminitis). (See Table 3).

The incorporation and consumption of effectivefiber benefits the cow by improving both productionand health of the animal. Management considera-tions should include how the TMR mixer will han-dle long, dry hay; should hay be pre-processed toreduce particle size and improve mixing; is dry for-age over-mixed which reduces dry hay to small, inef-fective particle length. Linn pointed out that feed-ing 10 lbs of long, dry hay per cow per day suppliesenough effective fiber to maintain normal, healthyrumen. When feeding processed forages (silage,processed hay, TMR mixer with hay processing abil-ity), Linn recommended that 50% of ensiled forageparticles by longer than .4 inches in length with 15%of the forage particles longer than 1.5 inches. It isimportant that forage particles consumed by the

cows have adequate length tostimulate rumen contractionsand rumination. Over mixingof good quality dry hay canreduce particle size and resultin inadequate effective fiberintake. Forages must be evalu-ated after mixing and deliveryto the feedbunk.

Animals not consumingadequate amounts of effectivefiber are at increased risk ofmetabolic disorders such asruminal acidosis, laminitis,inverted milk fat to milk pro-tein ratio and displaced abo-masum. The management goalis to have cows consume ade-quate effective fiber to main-tain health and production.

Feed Access And FeedingSystem

Availability of feed can oftenbe a limiting factor in maxi-mizing DMI. Some nutritionistsuse the term “slick-bunk syn-

drome” to describe feeding situations where cowsare simply underfed and lick the bunk clean givingit a “slick” appearance. In most controlled investi-gations, feed access is measured as the time cowshave physical access to adequate amounts of feed.Freer et al. (1962) observed an interaction of foragequality, feed access, and DMI. These results indicateintake is influenced by forage quality and should beconsidered. This difference would be especiallynoticeable if cattle were grouped and fed differentquality forages across groups.

More applicable to well managed farms, accessto ad lib amounts of high quality feeds should beconsidered. Erdman et al. (1989) reported increas-ing feed access time from 8 h to 20 h per dayincreased feed intake from 51.7 lb/d to 54.3 lb/d inmid-lactation cows. Increased access did notchange milk production and intake, as a % of body


Table 3: Effects of diet and feeding sequence on production and diges -tive function of lactating dairy cows. 1

Diet2 Significance3

Variable C-S H-C-S C-S+H Hay M

DMI (lb/d) 36.1 36.6 37.1 .10 NSCP (lb/d) 5.8 6.1 6.1 .01 NSMilk (lb/d) 38.1 41.6 40.3 .01 NSMilk efficiency

Kg/milk/Mcal NE1 .58 .63 .60 .01 NSMeal duration

(min) 15.4 18.2 18.0 .04 NSRumination

Periods per day 12.4 14.3 14.4 .05 NSChews per period 1306 1316 1350 NS NSMin/d 274 318 328 .05 NSMin/kg DM 16.7 19.3 19.5 .05 NSBoli per d 297 364 380 .05 NS

pH<6.0 (min) 280 213 214 NS NS

Extent of alfalfa silagedisappearance (%)

DM 68.9 73.7 70.3 .05 .05NDF 44.6 51.7 47.5 .05 NS

1: Adapted from Beauchemin and Buchanan-Smith (1990).2: C-S = concentrate fed followed by silage. H-C-S = hay fed prior to concentrate followed bysilage. C-S+H = concentrate followed by blended silage + hay.3: Significance: H = Hay; M = method.

weight, was not changed. Cows with increased feedaccess time did have higher weight gains (8h/d, +.8lb/d; 20h/d, +1.5 lb/d). In contrast, Martinsson andBurstedt (1990) measured intake and productionresponses of early lactation cows given differentaccess to feed (8h to 24h). In this study, diet ingre-dients (hay, silage, and concentrates) were fed sep-arately. Cows assigned 8h feed access time were fed0600 to 0930 and 1230 to 1700h each day. Cowswith restricted feed intakes in year 1 tended to havereduced feed intake (8h DMI = 30.4 lb/d vs 24h DMI= 32.6 lb/d). Intake differences due to feed accesswere greater during year 2 (8h DMI = 32.2 lb/d vs2h DMI = 35.4). The large difference in DMI resultedin a 2.4 lb increase in milk production. These work-ers suggested feed access is important especially forearly lactation cows.

Feed access and intake can also be influenced bycompetition for feed and feeding space (Albright,1993). Friend and Polan (1974) reported cows spentalmost 5 h/d at the feedbunk. The social rank of ani-mals within the group influenced time spent at thebunk after feed was placed in the bunk. Therefore,more dominant animals had more opportunity toconsume feed first after feeding. Subsequentresearch reports showed .7 ft per cow would allowadequate access and not depress intake (Friend etal., 1976). Most current recommendations establishfeeding space per cow at 1.5 to 2 ft per head. Theserecommendations agree with results of feedingbehavior research trials. A more recent report indi-cated that cows selected feeding positions in fence-line feeders based on dominance relationships

(Manson and Appleby, 1990). Cows withthe greatest differences in social domi-nance had average separation of 4.4 feed-ing positions (feed position = 2 ft per posi-tion). Albright (1993) reported cows fedtotal mixed rations in fenceline feedersate longer than cows fed in bunks withaccess around the entire bunk. Feedingsystem design and layout can potentiallyimpact intake by influencing feed accesstime via manipulation of animal to ani-mal interactions.

Feed PalatabilityOne critical aspect that must be considered on

the feed side of feedbunk managements palatabil-ity of the diet. For example, two reports from theUniversity of Maryland described the effects of silagepH on feed intake. Shaver et al. (1984) predictedoptimum silage organic matter intake would beachieved with a forage pH equal to 5.6, with an opti-mal range between pH 5 to 6. Erdman (1988)reported partial neutralization of corn silage (frompH = 3.64 to pH = 5.44) increased forage DMI 2.2lb/d. Total DMI was also increased (2.9 lb/d). Cornsilage pH was manipulated by the addition ofsodium bicarbonate. Milk yield was not different,but milk fat % and 4% FCM yield were increasedby buffering corn silage. Palatability of forage mayalso explain differences in intake of alfalfa hay andstraw reported by Freer et al. (1962).

Concentrate palatability can also influenceintake. Dustiness and texture of concentrate mix candepress intake of grain mixes. Feed additives havebeen found to depress grain intake. The recentdevelopment of cation:anion balancing and use ofanionic salts can influence concentrate consump-tion. Oetzel and Barmore (1993) ranked anionic saltmixtures based on intake and reported MgSO4 wasconsumed better than other anionic salts. Animalby-product feeds (animal proteins and fats) havebeen reported to decrease intake. In most cases, feedintake returned to normal following an adaptationperiod. Inclusion of new feeds (new silo, hay cut-ting, etc.) and feed additives in the diet should be



Table 4: Interaction of access to feed and forage quality on DMIand chewing activity 1.

------------time (min)------------feed access (h) DMI (lb) eating ruminating restingHay 24 29.6 405 565 470

4.5 25.3 261 534 6452.0 17.9 122 434 884

Straw 24 13.8 343 474 6234.5 11.2 251 392 7972.0 8.5 121 358 961

1: Adapted from Freer et al. (1962).

done gradually over an adaptation period. This strat-egy helps prevent potential off-feed problems andbetter maintains animal performance.

Water AccessibilityWater consumption has also been found to influ-

ence DMI and milk production. Dado and Allen(1994) reported a highly significant correlationbetween water intake and milk yield (Pearson cor-relation coefficient r = .94). A significant relation-ship was also described between DMI and waterintake (Pearson correlation coefficient r = .96).Drinking time required 10% of time spent eating(Table 5). While eating events required more time,cows had more drinking bouts (14.0, all lactations)than eating bouts (11.0, all lactations). These differ-ences indicate the importance of animals access towater. Time spent drinking was not described rela-tive to eating activities during the day. However,water supply should be convenient to feed to stim-ulate DMI. A general guide is to provide waterwithin 50 ft of the feedbunk.

Feeding Management ConsiderationsRobinson (1989) described potential interactions

between feeding strategies, feedstuff characteristics,and quality of animal management. Options andpossibilities are unlimited for consideration of feed-ing systems and strategies within a given animalfacility. Within a feeding system, many factors influ-ence DMI. Diet formulation, mixing, and feeding toensure normal rumen function is a high priority forachieving maximum intake and productivity. Con-trol of diet ingredient intake is also a primary goalof the feeding management system. Feed accesscontributes to animal performance and success ofthe feeding program. Palatability of feed can stimu-late or depress intake. Blending and use of feedingredients with poor palatability should be donecarefully to minimize off-feed problems. Maintain-ing fresh feed during periods of high eating activity(ie. after milking) stimulates larger meal sizes as aresult of improved palatability. Water supply mustalso be fresh, clean and accessible to maintainintake and production. Feeding management strate-gies are dynamic to feeding system, diet, and farm-

stead layout (NRAES - 38, 1990). Manage all factorsthat influence DMI to achieve and maintain highintakes and animal performance.

REFERENCES:1. Albright, J.L. 1993. Feeding behavior of dairy

cattle. J. Dairy Sci. 76:485.2. Beauchemin, K.A. and J.G. Buchanan-Smith.

1990. Effects of fiber source and method of feedingon chewing activities, digestive function, and pro-ductivity of dairy cows. J. Dairy Sci. 73:749.

3. Buckmaster, D.R. and L.D. Muller. 1994.Uncertainty in nutritive measures of mixed livestockrations. J. Dairy Sci. 77:3716.

4. Chase, L.E. 1993. Developing nutrition pro-grams for high producing dairy herds. J. Dairy Sci.76:3287.

5. Coppock, C.E., D.L. Bath, B. Harris. 1981.From feeding to feeding systems. J. Dairy Sci.64:1230.

6. Dado, R.G. and M.S. Allen. 1994. Variation inand relationships among feeding, chewing anddrinking variables for lactating dairy cows. J. DairySci. 77:132.

7. Erdman, R. 1988. Forage pH effects on intakein early lactation dairy cows. J. Dairy Sci. 71:1198.

8. Erdman, R.A., T.W. Moreland and W.R. Strick-lin. 1989. Effect of time of feed access on intake andproduction in lactating dairy cows. J. Dairy Sci.72:1210.


Table 5: Milk production and feeding be -havior statistics of lactating Holsteincows 1.

Primiparous MultiparousItem Mean MeanMilk (lb/d) 63.1 82.5DMI (lb/d) 44.0 54.6Time eating (min/d) 284 314Water intake (L) 63.2 89.5Time drinking (min/d) 17.7 19.1

1: Adapted from Dado and Allen (1994).

9. Freer, M., R.C. Campling and C.C. Balch. 1962.Factors affecting the voluntary intake of food bycows. 4. The behavior and reticular motility of cowsreceiving diets of hay, oat straw and oat straw withurea. Br. J. Nutr. 16:279

10. Friend, T.H. and C.E. Polan. 1974. Socialrank, feeding behavior, and free stall utilization bydairy cattle. J. Dairy Sci. 57:1214.

11. Friend, T.H., C.E. Polan and M.L. McGilliard.1977. Free stall and feed bunk requirements rela-tive to behavior, production and individual feedintake in dairy cows. J. Dairy Sci. 60:108.

12. Howard, W.T. 1990. Pros and cons of onegroup TMR feeding. Dairy Profit Report 3(4):1.

13. Kertz, A.F., L.F. Reutzel, and G.M. Thomson.1991. Dry matter intake from parturition to midlac-tation. J. Dairy Sci. 74:2290.

14. Lahr, D.A., D.E. Otterby, D.G. Johnson, J.G.Linn, and R.G. Lundquist. 1983. Effects of moisturecontent of complete diets on feed intake and milkproduction by cows. J. Dairy Sci. 66:1891.

15. Linn, J.G. 1992. Coping With Changing FeedQuality in Large Dairy Herd Management, pg. 318.ADSA, Champaign-Urbana, IL.

16. McCullough, M.E. 1991. Feeding strategiesfor the dairy herd require careful selection. Feed-stuffs. November, 18

17. McGilliard, M.L., J.M. Swisher, and R.E.James. 1983. Grouping lactating cows by nutritionalrequirements for feeding. J. Dairy Sci. 66:1084.

18. Manson, F.J. and M.C. Appleby. 1990. Spac-ing of dairy cows at a food trough. Appl. Anim.Behav. Sci. 26:69.

19. Oetzel, G.R., F.P. Villalba, W.J. Goodger, andK.V. Nordlund. 1993. A comparison of on-farmmethods for estimating the dry matter content of feedingredients. J. Dairy Sci. 76:293.

20. Martinsson, K. and E. Burstedt. 1990. Effectsof length of access time to feed and allotment of hayon grass silage intake and production in lactatingdairy cows. Swedish J. Agric. Res. 20:169.

21. NRAES Publication 38. 1990. Dairy FeedingSystems Proc. from the Dairy Feeding Systems Sym-posium, Harrisburg, PA.

22. Oetzel, G.R. and J.A. Barmore. 1993. Intakeof a concentrate mixture containing various anionicsalts fed to pregnant, nonlactating dairy cows. J.Dairy Sci. 76:1617.

23. Rakes, A.H. 1969. Complete rations for dairycattle. J. Dairy Sci. 52(6):870.

24. Robinson, P.H. 1989. Dynamic aspects offeeding management for dairy cows. J. Dairy Sci.72:1197.

25. Robinson, P.H., P.L. Burgess, and R.E.McQueen. 1990. Influence of moisture content ofmixed rations on feed intake and milk productionof dairy cows. J. Dairy Sci. 73:2916.

26. Schucker, B.L., M.L. McGilliard, R.E. James,and C.C. Stallings. 1988. A field study of groupingcows by nutrient requirements for feeding. J. DairySci. 71:870.

27. Shaver, R.D., R.A. Erdman, and J.H. Vander-sall. 1984. Effects of silage pH on voluntary intakeof corn silage. J. Dairy Sci. 67:2045.

28. Spahr, S.L., R.D. Shanks, G.C. McCoy, E.Maltz, and O. Kroll. 1993. Lactation potential as acriterion for strategy of feeding total mixed rationsto dairy cows. J. Dairy Sci. 76:2723.

29. Stallings, C.C. and M.L. McGilliard. 1984.Lead factors for total mixed ration formulation. J.Dairy Sci. 67:902.

30. Williams, C.B. and P.A. Oltenocu. 1992. Eval-uation of criteria used to group lactating cows usinga dairy production model. J. Dairy Sci. 75:155.



MinimizingTransitional Stress

For Close-upDry Cows

Field Experiences and Applications

By Jimmy L. Horner, Ph.D., P.A.S.Horner Nutrition Services, Inc.

P.O. Box 59Decatur, TX 76234

817-627-6455fax 817-627-7474


TT ransitional stress in cows going from theclose-up dry cow period into early lactationcan have a tremendous impact on their sub-

sequent lactation. The primary transition period forcows comprises the last 21 days prior to calvingthrough the first 21 days after calving. Obviously,minimizing problems at calving is one way to reducetransitional stress in cows. However, our single mostimportant goal in attempting to minimize transitionalstress should be to freshen cows with excellentappetites. When we can get fresh cows eating wellimmediately after calving, everything else is mucheasier.

Feeding programs for cows during the transitionperiod need not be complex or changed frequently.The challenge is to avoid freshening problems andto get cows eating as much as possible as soon aspossible. How we manage cows during these criti-cal six weeks of the transition period, to a very largeextent, determines a cow’s health, reproductive per-formance, milk production and profitability for theentire lactation.

Transition Period Feeding StrategiesVarious approaches to feeding the transition cow

exist in our industry. Some of these approaches workbetter than others, but overall we have found thatsimplicity on our behalf and close attention to cowsby the producer is always the best general approach.Although some of the current concepts and tech-nologies used in feeding the transition cow can beextremely effective and beneficial, if the producerbecomes confused or gets caught up in trying tomicro-manage too many details, success may beshort-lived.

We have experimented with many types of feed-stuffs, additives, ration manipulations, managementstrategies, etc. Through personal experience we havegained the most success with the use of the following:

• Anionic salts (when used properly) accompaniedwith elevated levels of both calcium and magnesium.

• Direct-fed microbials (when scrutinized closelyfor concentration of colony forming units or CFU’s,host specificity, types of bacteria present, and cost).

• Niacin (at 6-12 grams per day) to help preventketosis, increase microbial protein synthesis, andincrease blood glucose levels.

• Bypass protein to balance protein requirementsand to assist in intake of bypass protein sources past-calving.

• Adequate effective fiber from long-stemmed for-age (minimum of 8-12 lbs. per day).

• Similar ingredients as contained in the freshcow ration to minimize ruminal adaptation time.

• Heavily fortified vitamin and mineral levels.Although anionic salts (anions) were used initially

to control milk fever in problem herds, we havefound their use to be beneficial in other areas as well,such as reduction in retained placenta, improvedfeed intake immediately after calving, and enhancedstart-up milk production. Various sources of anionsare available, but we have experienced the mostsuccess with calcium sulfate, magnesium chloride,calcium chloride, and magnesium sulfate. A morepronounced palatability problem has been observedwith the use of ammonium chloride and ammoniumsulfate, and we also have more difficulty balancingrumen bypass protein needs in close-up dry cowswhen using the ammonium salts.

We will typically use from .25-.75 lb. of anionsin most rations to attain a DCAD (dietary cation-anion difference) of -10 to 0 milliequivalents per 100grams of diet dry matter. Our results with anionshave also been much better when combined with150-200 grams of calcium and 40-60 grams of mag-nesium in the daily ration.

The single most important lesson we have learnedfrom the use of anions is that this concept of feed-ing close-up dry cows is certainly not for everybody.We recommend the use of anions only in very well-managed herds under the following criteria:

1. All forages will be analyzed for mineralcontent.

2. Changes in forages fed to close-up cowswill be minimal.

3. Cows will receive the anions for a mini-mum of 10 days and a maximum of 30 days.

4. Cows will not be pastured during theclose-up period.


Minimizing Transitional Stress For Close-up Dry Cows

5. The nutritionist will be notifiedof any deviations from the above cri-teria in a timely manner.The use of direct-fed microbials (DFMs)

has increased over the past few years butmany questions remain concerning theiruse. We have found that the transition cowis a good candidate for the use of DFMs dueto the stress from pre-freshening to freshen-ing, and the subsequent limitations on feedintake during this time. To replenishdepleted gut microflora we recommend thatour herds use a highly concentrated,bovine-specific DFM containing viable lac-tobacillus acidophilus and streptococcusfaecium bacteria. Best results have occurredby inoculating cows approximately 21 daysprior to calving, feeding the DFM daily dur-ing the close-up period, and inoculatingfresh cows on days 0, 3 and 7 post-calvingcombined with feeding the DFM daily dur-ing the initial 21 days after freshening.

Use of DFMs after the transition period dependsupon level of production, type of feeding program,environmental conditions, and overall cost effec-tiveness in the ration. We have observed obviousbenefits from the use of DFMs including increasedfeed consumption before and after calving,increased start-up milk production, and reducedincidence of bloat and acidosis. Hopefully, moreresearch with DFMs will be done in the future todetermine optimum conditions for their use; whyresponses in the past have been somewhat incon-sistent; which bacteria are most important in a vari-ety of feeding programs; and what levels of bacte-ria are required for maximum benefit.

The B-vitamin niacin has been used for severalyears to help prevent ketosis in problem herds. Werecommend niacin in close-up dry cow programs ata level of 6-12 grams per day and fresh cow rationsat a level of 6 grams per day. In addition to preven-tion of ketosis, niacin can also improve feed intakeand microbial protein production. We have also seenevidence of niacin elevating milk protein synthesiswhen used in high fat diets during early lactation.

The incorporation of rumen bypass protein inclose-up dry cow rations is usually necessary to bal-ance protein requirements and to assist in con-sumption of bypass protein sources after calving.We formulate close-up dry cow rations to contain aminimum of 35% high quality rumen bypass pro-tein, and fresh cow rations to contain a minimum of38% high quality rumen bypass protein. Since manybypass protein sources are not very palatable, it iseven more critical that they are present in the close-up dry cow ration to facilitate maximum consump-tion in early lactation cows.

Adequate effective fiber (that fiber which stimu-lates cud chewing) from long-stemmed forage is amust in close-up dry cow rations in attempting tominimize abomasal displacements and maximizeappetite after calving. We recommend a minimumlevel of 8-12 lbs. of long-stemmed forage and a max-imum of 20-25 lbs. of silage in close-up rations.

Avoiding abrupt ration changes by feeding simi-lar ingredients as contained in the fresh cow rationis critical in close-up dry cow rations to shortenruminal adaptation time and to enhance appetite


Nutrient Guidelines For Close-upDry Cows And Fresh Cows

nutrient close-ups fresh cowscrude protein 14-15% 19-20%undegradable protein 35-38% 38-40%N.E. lactation (Mcal/lb) .68-.70 .80-.84calcium .40-1.80%* .8-1.0%phosphorus .4-.5% .5-.6%magnesium .3-.5%* .3-.4%potassium .8-1.2% 1.0-1.4%sulfur .25-.45% .25-.30%copper 25ppm 25ppmzinc 80ppm 80ppmmanganese 60pp 60ppmiron 100ppm 100ppmselenium .3ppm .3ppmVitamin A (IUs/day) 160,000 200,000Vitamin D(IUs/day) 40,000 50,000Vitamin E(IUs/day) 1,000 1,000niacin (g/day) 6-12 6

*: Calcium, magnesium and sulfur must be elevated whenfeeding anionic salts

notes

after calving. A portion of the fresh or high groupration (approximately 1/3 to 1/2 of the diet dry matter)without rumen buffer works extremely well.

Heavily fortified (yet balanced) vitamins and min-eral levels during the close-up period can certainlyminimize transitional stress by alleviating problemssuch as retained placenta, uterine infection, droopycow syndrome, etc. Adequate levels of vitamins andtrace minerals are also necessary for maintenanceof a healthy immune system, normal colostrumquality, and good reproductive efficiency.

SummaryIn assessing whether a particular producer is suc-

cessfully minimizing transitional stress in close-updry cows a few questions come to mind:

• Do your cows freshen in high gear and eat likethere is no tomorrow?

• Does their milk production jump rapidly with-out significant loss of body condition?

• Do you have a minimum incidence of fresh-ening problems, i.e. displaced abomasum, ketosis,off-feed, retained placenta, milk fever, etc.?

A good transition feeding program can help anyproducer respond with a confident “yes” to each ofthese questions.

Minimizing Transitional Stress For Close-up Dry Cows


Facts AndFallacies About

The UterusAfter Calving

By Donald J. Klingborg, DVMVeterinary Medicine ExtensionSchool of Veterinary Medicine

University of CaliforniaDavis, CA 95616

916-752-0853fax 916-752-7563


UU nbelievable. That single word best de-scribes the structure and function of whatis one of the most complex organs in the

body. The uterus is simply unbelievable. It acceptsa substance foreign to itself, blocks the normal bodydefenses designed to destroy foreign “invaders”, andnourishes, protects, and sustains the developing calfwhile the uterus grows from a diameter of about oneinch to 24 inches or more. When the time is right,the uterus accepts a signal from the calf and trans-forms itself into a delivery system, forcibly expellingthe calf, and then begins an amazing process to pre-pare itself for a repeat of the whole cycle. It’s thatrecovery process between calving and pregnancythat is so critical to a profitable dairy enterprise, andis so misunderstood.

Following calving the uterus must expel the fetalmembranes and fluid that surrounded the calf, reab-sorb the small concentrated button-like areas wherethe calf and mother exchanged nutrients and oxy-gen, repair the uterine lining, and shrink to a sizeready to accept the next embryo. The normal uteruswill lose more than 80% of its size at calving withina two to three-week period. The process controllingthis recovery is complex, and filled with a variety ofcontrol systems sending signals between the uter-ine glands, the ovaries, several areas in the brain,and the adrenal glands (located by the kidneys).

Other hormones associated with milk letdownhave an influence on uterine muscular activitythough the hormone oxytocin, which also plays arole in recovery. Plenty can go wrong, but I’m alwaysamazed at how much goes right – frequently in spiteof, rather than because, of what we caretakers do.

The rate of involution, a term that encompassesuterine shrinkage, fluid loss and tissue repair, is anindicator of the overall status of the recovery. Any-thing that slows involution will delay or prevent asuccessful subsequent pregnancy. Traditionally, wecaretakers have concentrated much of our energyon dealing with uterine infections through the useof antibiotics and other treatments as our attempt to“prevent” or “cure” them. The most frequent ques-tion most dairy veterinarians are asked is “which

medicine should I use, Doc”? Many of the most pop-ular concoctions have romantic or powerful names,pretty colors, secret ingredients, and a long list oftestimonials from your colleagues singing theirpraises. The frustration associated with trying to getthat good cow pregnant drives dairy farmers toattempt anything, even when it makes neither med-ical nor economic sense.

Almost all cows will become contaminated anddevelop a uterine infection at the time of calving.The cervix, the valve that seals the uterine interiorfrom the outside environment, opens wide at calv-ing to allow the calf to pass, thereby admitting what-ever bugs are in the neighborhood, and the neigh-borhood has plenty. Multiple bacteria types, includ-ing bugs such as the coliforms, Streptococci, Actin-omyces pyogenes, Fusobacterium necrophorum,and Bacteroides melaninogenicus, are found in uter-ine cultures during the post partum period. It is notunusual to find bacteria present in over 90% of uter-ine samples at 15 days after calving, close to 80%at 30 days, 50% at 45 days, and about 10% at 60days. You might conclude that with these kinds ofinfection rates you should treat everything withantibiotics or antiseptics immediately. Don’t.

Why not? Before I explain why I believe across-the-board treatment is not in your cows’ best inter-est, answer two questions for me:

First, which medication do you want to use? Youname it, someone has infused it, and I can findsomeone who will swear by it. Antibiotics infusedinto a cows uterus act a lot like antibiotics injectedinto muscle, but with less predictability. They moveinto the blood, course through body organs, and findtheir way into milk. Residues are always a concern,both in meat and milk, following uterine infusion.The only question is when will they be there andwhether they will be at a level that can be detected.Systemic treatment, using either IM or IV regimens,also enjoys its advocates, and has similar residueconcerns. Other non-antibiotic products, includinguterine boluses, antiseptic infusions, and hormonetreatments have been promoted and defended, butall of these treatments lack definitive research results


Facts And Fallacies About The Uterus After Calving


FALLACY:The uterus is like an old sock, simply receiving and holding the calf until it is ready to be born.

FACT:The uterus is a dynamic, complex organ with interactions between the walls and deep tissues, the ovaries, the brain, and otherorgans within the body.

FALLACY:I can treat the signs of uterine dysfunction, such as abnormal discharge, poor involution, anestrus, etc., effectively and economi-cally.

FACT:A dysfunctional uterus will never approach the same level of performance as one that is normal, regardless of treatment. Thereare treatments that can improve fertility, but prevention of the problem is the best method, and prevention of most uterine prob-lems is possible and profitable.

FALLACY:Treating by uterine boluses, infusions, hormones, or systemic therapy will improve subsequent fertility.

FACT:No treatment returns an abnormal uterus to the same fertility level as compared to a normal uterus. There are studies which sup-port one treatment over another, and other studies with contradictory results, such that there exists no definitive evidence that oneproduct or procedure is more effective than another. Best management practices prevent rather than treat problems.

FALLACY:I can treat the signs of the problem, such as retained fetal membranes or a foul smelling discharge and solve the problem.

FACT:That approach is like taking aspirin to fix a headache that results from wearing a hat that is too small. The hat size needs to bechanged, not better aspirin developed.

FALLACY:Vaginal discharge is a sign of a uterine infection.

FACT:Lochia is a normal and expected vaginal discharge during the early post partum period. Discharge that is very watery, in largequantities, and foul smelling does represent a problem.

FALLACY:Red medicine works best.

FACT:Color is not a factor in determining the effectiveness of a medication, and no medicine returns the abnormal animal to normal per-formance.

FALLACY:Local uterine treatment will not result in milk or tissue residues. Non-antibiotics will not result in residues.

FACT:Any medication you put in the uterus will find its way into the general circulation, and will result in tissue and milk residues.

FALLACY:Dry cows are the perfect group to get rid of all of the junk feed on the dairy because they don’t produce any milk and don’t needthe good stuff anyway.

FACT:These are your most important animals on the farm, and they have real need for adequate support in order to be prepared for asuccessful lactation with normal fertility. Good management from the last third of the previous lactation through the first three weeksof the subsequent lactation will result in excellent milk production and reproductive performance.

FACT:Metritis, pyometra, and forced culling from poor fertility is in large part preventable. Maternity pen sanitation, good hygiene if obstet-rical procedures are needed, careful selection of which cows get treated and the treatment methods, including technique and san-itary practices, and dry cow nutritional balance will result in the post partum period being a pleasure, not a problem.

demonstrating their benefits. In fact, there are re-search results published to support or detract fromalmost every product and treatment program eversuggested.

Why can’t we develop the data to definitivelyanswer the questions about treatment? One reasonis that interpretation of results is difficult. There arethree potential outcomes to any treatment; the treat-ment may help and improvement will follow; it mayhave no beneficial nor detrimental effect; or thetreatment itself can be detrimental. All three canhappen with a single treatment in a herd simply bychance, and it requires well designed trials com-paring treatments to untreated controls to recognizethe real effects of treatment. As you might imagineit is difficult to find cooperators that are willing toleave an adequate number of untreated controls intheir herd for a treatment trial.

Another problem is our inability to precisely iden-tify those animals in need of therapeutic assistancefrom their normal herdmates. The high percentageof positive culture results from uterine samplesdemonstrates the poor specificity of that test in iden-tifying animals in need. Rectal palpation, vaginalexamination, discharge evaluation, fever, appetiteand other methods are commonly used to identifyand initiate therapy in poorly involuting animals,but they are not perfect. The earlier you examinethe animal, the more imprecise the decision to treator leave alone can be, and you will end up treatingmany that didn’t need it, a disadvantage to your eco-nomics and your cow’s fertility. You also get fabu-lous recoveries (because they would have been OKwithout treatment anyway), and a false evaluationof the therapy.

If I told you that two dairies of the same size haddifferent abortion rates last year, and although DairyA’s rate was 2% higher than Dairy B’s, I concludedthat Dairy A was in better shape than Dairy B, wouldyou disagree? Would you change your mind if Iadded that Dairy A had 55% of the herd pregnant,and Dairy B only had 30%? I’m sure you will agreethat pregnancy is an essential qualification for riskof abortion. The same problem exists in treatment

trails; if we don’t know which really need it, andmix in large numbers of those that do not, we makeinterpretation of results very difficult. I’ve always feltthat if “recovery rates” for treatment of infections,cystic ovaries, etc., we high, say over 50% at a twoweek recheck, then I probably treated a bunch ofanimals that didn’t need it.

Second question: how are you going to evaluatethe results? Part of the confusion in evaluating var-ious treatments result from our inability to routinelyselect the correct goal of therapy. What yardstick arewe going to use to measure success?

When I was working as a milker we used to callthe vet to come clean cows with retained fetal mem-branes. Our yardstick of success was to eliminatethe tail switch from stinking so that whenever shehit us in the face she would not transfer that won-derful odor to our nose area. By this measure man-ual removal of a retained placenta was a smashingsuccess, and was a common practice, until somesmart person looked at its influence on days openand found treated animals were significantly andadversely affected. We were simply using the wrongyardstick to evaluate the therapy.

Need another example? Twenty years ago or soveterinarians were regularly called to bring anestruscows into heat, and occasionally they used an injec-tion of a hormone available at that time that madethem express heat signs. It worked – if a cow actinglike she was in heat was your goal. If you reallywanted a pregnancy, however, the use of that prod-uct was counterproductive.

I recommend against treating every cow. In myexperience the routine use of uterine boluses cre-ates problems where none existed, and simple dis-continuing that practice directly improves herd fer-tility. Similarly, routine infusions result in increasedday open. In my hands it appears that a single uter-ine infusion in heifers early in the postpartum periodwill increase days open by eight without anyimprovement of conception rates or numbers get-ting pregnant. There is ample evidence to be con-cerned that most treatments administered to normalcows will result in increased days open, and that



our ability to identify normal is imprecise. Addi-tionally, there is no clear scientific evidence that anygiven treatment is beneficial to the majority of ani-mals being treated. Animals that are off feed, fever-ish, with very thin watery and foul smelling dis-charge need and will benefit from treatment! Thereexist other uterine problems that can be treated withimproved performance as the outcome. My point issimply that your time is better spent preventing theproblems in the first place, with proven effective-ness, rather than spending your time, money, andeffort using treatments which do not always resultin improvement, and which may be detrimental tothe animals subsequent performance.

There has been an explosion in our understandingabout how to maintain a healthy uterus under com-mercial dairy conditions. Prevention managementpractices allows us to reduce the numbers of animalsneeding treatments to less than 25% in most com-mercial herds, and much lower in exceptionally man-aged herds. Cow fertility is significantly improved inthose that never needed treatment versus those thatdo. No therapy returns a cow to the level of normalperformance. Prove this to yourself by comparingdays open, services per conception, and culling ratesfor normal animals that deliver live calves unassisted,do not retain their placenta, receive no treatment, andare pregnant within two services (my definition of nor-mal) against their treated herdmates.

We now know what many have long suspected:a relationship exists between poor fertility and anumber of other cow problems. The risk of poor fer-tility is increased if the animal has any one or com-binations of: milk fever, prolonged but unassistedcalving, assisted calving, retained fetal membranes,prolapsed uterus, mastitis, ketosis, fat cow syn-drome, displaced abomasum, unsanitary calvingconditions, or unnecessary post partum treatment.The key management points to prevent these con-ditions revolve around energy and protein balance;control of rapid weight gain or loss; proper bodycondition at calving and into the early lactation per-iod; calcium and phosphorus balance; anion/ cationbalance of the dry cow ration; trace mineral and vit-

amin balance; calf size (sire selection); sanitation atcalving; and post partum treatment methods.

Heifers must be of adequate frame size, andproper body condition, to successfully deliver a calfwhile supporting their needs for growth and milkproduction. High rates of anestrus heifers in the first70 days of lactation, which were at their properframe and body condition at the time of calving,represent a ration imbalance or unsuccessful com-petition with older cows at the feed bunk, or both.

The preparation for the following lactation incows begins in the last third of the previous preg-nancy. This is the time to carefully monitor theirbody condition and adjust their rations to achievetheir ideal condition. An extra bonus to good man-agement is that this period also represents the mosteconomical time to put weight on animals that areunderconditioned, and to take weight off of thosethat are overconditioned.

We now know that our old recommendations tohave cows at body condition scores of 4+ duringthe dry period represented the use of the wrongyardstick. It may have helped them from getting toothin during their first 1/3 of the following lactation,but also lowered both their production and fertility.Cows should be dried at body condition scores of3-3.5, and calved at 3.5 for maximum productionand fertility. Rapid changes in weight, in either direc-tion, are likely to result in fat cow syndrome, whichcan result in delayed involution, increased uterineinfection rates, and poorer recovery.


In my hands it appears thata single uterine infusion inheifers early in the postpar -

tum period will increasedays open by eight without

anyimprovement of

conception rates or num -bers getting pregnant.

The dry period is a terrible time to get rid of thatjunk feed you’ve got laying around. These are yourmost important cows on the farm, and this is themost important period in the whole lactation. Theration needs to be carefully balanced for energy,fiber, and quality protein to provide the cow withthe ability to deliver a healthy calf, recover frompregnancy, and reach her maximum potential pro-

duction. Adequate trace minerals and vitamins areessential. Prevention of heat stress, corral mainte-nance to promote feed intake, sanitary bedding, ade-quate water, and all the other well known husbandryrequirements that are frequently missing from drycow pens are money makers if you use the rightyardstick as your goal.



notes

The New EthicFor Animals

And The DairyIndustry

By Bernard E. RollinPhilosophy Department,Colorado State UniversityFort Collins, CO 80523

303-491-6885


TT here is an unfortunate tendency on the partof those who use animals to dismiss the newsocial concern with animal treatment as the

irrational ravings of tofu-eating, ginseng-guzzling,urban wimps and bunny-hugging extremists. “Ani-mal welfare is what we already do; animal rights ifwhat they want us to do,” one animal scientist said,neatly summarizing the situation. However, what isof paramount importance is that “they” are not justa band of radicals; the new ethic for animals hastaken root among society in general. As one cow-boy in Kingsville, Texas put it to me: “Hell, Doc, ifit were just the damn radicals, we could shoot thesons of bitches!”

My first point, then, is to explain the new ethicand its conceptual roots. Although society has paidformal attention to limiting human behavior regard-ing animals for over 2,000 years, such attention wasrestricted to the prohibition of overt, intentional, will-ful, extraordinary, malicious, or unnecessary cruelty;deviant sadism; or outrageous neglect. For example,not providing food or water. This ethic can be foundeven in the Bible. For example, in the injunction notto yoke the ox and the ass to a plow together, or inthe restriction against muzzling the ox when he isbeing used to mill grain.

This minimalistic, lowest common denominatorethic was formally encapsulated in the anti-crueltylaws during the 19th century. These laws were asmuch designed to ferret out sadists and psychopaths– who might begin with animals and, if left un-checked, graduate to venting their twisted urgesupon human beings – as to protect the animals forthemselves.

This view of prohibiting animal cruelty can befound in Catholic theology where, although animalsdo not in themselves count morally, animal crueltyis forbidden for its potential consequences for peo-ple, since people who are cruel to animals will ‘grad-uate’ to abusing people. Interestingly enough, con-temporary research has buttressed this insight. Thetraditional humane or animal welfare movementwas also caught up in the categories of kindness andcruelty, and for this reason tended (and still tends)

to simplistically categorize anyone causing animalsuffering as ‘cruel’. Hence, one can still find activistspicketing medical research institutions and carryingsigns which say “stop the cruelty” — as if researchersare on a par with people like the serial killers, manyof whom did indeed torture animals in their youth.

Within the purview of this traditional ethic, anysuffering inflicted on animals for “acceptable,” “nor-mal” or “necessary” reasons such as economic ben-efit, food production, pursuit of scientific knowledge,cures for disease, or, as one law puts it, otherwise“ministering to the necessities of man,” was morallyand legally invisible, shrouded by the all-encom-passing cloak of “necessity.” By and large, therefore,the “normal” use of animals for human benefit inresearch, agriculture, hunting, trapping, rodeo andthe like was not the concern of social moral thoughton animals.

During the past two decades society has begun tomove beyond the overly simplistic ethic of crueltyand kindness and to reach for a more adequate setof moral categories for guiding, assessing, and con-straining our treatment of other animals. Perhaps thekey insight behind this change is the realization thatthe overwhelming majority of animal suffering athuman hands is not the result of cruelty, but rather,these animals suffer because of normal animal useand socially acceptable motives. To prove this, I askyou to perform a thought experiment. Imagine a piechart representing the total amount of suffering thatanimals experience at human hands. Then ask your-self, what percentage of that suffering is the result ofintentional, sadistic, useless, deliberate infliction ofpain or suffering on the animals for no purpose? Inter-estingly enough, all of my audiences, be they Mon-tana rodeo people or San Francisco activists, say thesame thing — well under 1%. Most animal sufferingcomes from reasonable human motives and goals.Scientists may be motivated by benevolence, highideals and noble goals, yet far more animal sufferingis occasioned by people acting in pursuit of thesemotives than by the actions of overt sadists. Con-finement agriculturalists may be motivated by thequest for efficiency, profit, productivity, low-cost foodand other putatively acceptable goals, yet again, their


The New Ethic For Animals And The Dairy Industry

activities occasion animal suffering in orders of mag-nitude traditionally unimaginable.

As we mentioned, the old ethic doesn’t apply tothese normal, non-deviant uses of animals. This istrue not only conceptually, but practically. The lim-itations of the ethic and the laws based in it weredramatically illustrated when the Animal Legal De-fense Fund, a group of attorneys whose raison d’etreis raising the moral status of animals in society byuse of the legal system, attempted to extend thescope of the anti-cruelty laws by a test case. As ani-mal advocates, they generate many fascinating law-suits which test, press, and expose the limits of thelegal system’s control over the treatment of animals.In 1985, they brought suit against the New York StateDepartment of Environmental Conservation, thatbranch of New York State government charged withadministering the use of public lands. Specifically,they charged the department with violating the anti-cruelty laws by permitting trapping on public landsutilizing the steel-jawed trap. Since there are no lawsregulating how often a trapper must check his trapline, an injured animal could be trapped withoutfood, water, medical care or euthanasia for longperiods of time which, according to the plaintiffs,constituted unnecessary cruelty. They were thusseeking an end to such trapping.

Given the laws, the judge made a very wise deci-sion. He opined that the steel-jawed trap was in hisview an unacceptable device. But given the way theanti-cruelty laws have been written and interpreted,the actions of the agency in question did not consti-tute cruelty. After all, steel-jawed trapping is widelydone as a means to achieving pest control, supply-ing fur, and providing a recreational pastime. Thus,the activity of trapping is a legitimate one from a legalpoint of view, and does not fit either the intent, judi-cial history or statutory language of the anti-crueltylaws. If one wishes to change the status of the steel-jawed trap, the judge asserted, one should thereforego not to the judiciary, but to the legislature. In otherwords, one must change the laws, i.e. the social ethic.

This case neatly illustrates some important fea-tures of what is happening in social thought: First ofall, social thought is moving beyond cruelty. Sec-ond, society is attempting to create new social rulesand laws to protect animals. (The best illustration ofthis point is the passage in 1985 of two new federallaws to protect laboratory animals after society real-ized that the research community was not regulat-ing itself.) Third, society is moving beyond concernabout traditional cute and cuddly animals to con-cern about all animals who can suffer.

Why is society suddenly concerned about the99% of animal suffering that is not the result of delib-erate cruelty? One can speculate as to why the de-mand for such an ethic has emerged only recently.

First, society has just lately focused its concernon disenfranchised human individuals and groups,such as women, Blacks, the handicapped, and theThird World. This same emphasis on moral obliga-tion rather than patronizing benevolence toward thepowerless has led to a new look at animal treatment.

Second, the urbanization of society makes thecompanion animal, not the food animal, the para-digm for animals in the social mind.

Third, graphic media portrayal of animal exploita-tion fuels social concern. As one reporter said to me,“animals sell papers.”

Fourth, increased awareness of the magnitude ofanimal exploitation made possible by technologies ofscale inspires massive unease among citizens, whoperhaps see themselves being rendered insignificantin the face of techniques, systems and machines thatrelentlessly reduce the individual — animal or human— to a replaceable quantity. This sense of impotencein the face of forces one cannot even understand, letalone control, can fuel empathy with the animals.

Fifth, numerous rational voices have been raisedto spearhead the articulation of a new ethic for ani-mals. Although concern for animals was tradition-ally seen (with much justice) as largely a matter ofinchoate emotion, such a charge cannot be leveledagainst the numerous philosophers and other intel-lectuals of today who eloquently and forcefullynudge the social mind in the direction of increasingmoral awareness of our obligations to animals.


Sixth, and most important, the nature of animaluse has changed significantly. The major use of ani-mals in society was and is, of course, agricultural.Before the mid-20th century, the essence of agricul-ture was husbandry. People who used animals putthose animals into environments for which theywere evolved and adapted and then augmentedtheir natural ability to cope with additional food,shelter, protection from predators, etc. Producers didwell if and only if animals did well. This is what Tem-ple Grandin has aptly called “the ancient contract”— or as ranchers say: “we take care of the animalsand they take care of us.” No producer could, forexample, have attempted to raise 10,000 egg lay-ing chickens in one building — he would have hadall his animals succumb to disease in weeks.

In contrast, when animal husbandry departmentssymbolically became animal science departmentsin the 1940s and 50s, industry replaced husbandry,and the values of efficiency and productivity aboveall else entered agricultural thinking and practice.Whereas traditional agriculture was about puttingsquare pegs in square holes, round pegs in roundholes, and creating as little friction as possible whiledoing so, ‘technological sanders’ such as antibioticsand vaccines allowed us to produce animals in envi-ronments which didn’t suit their natures but wereconvenient for us. For example, we could now raise10,000 chickens in one building.

Similarly, the rise of significant amounts of re-search and toxicity testing on animals in the mid-20th century also differs from the ancient contract— we inflict disease on animals, wound, burn andpoison them for our benefit, with no benefit to them.

These, then, are the reasons society seeks a newethic for animals. What form is this emerging ethictaking? Very simply, it asks that the consensus ethicwe all share in society be extended to include ani-mals, as it was extended to include disenfranchisedhumans. Despite an inherent tendency on our partto magnify and stress differences in the ethical posi-tions among diverse persons in a society, the simi-larities and agreements in ethical principles, intu-itions, practices and theories that obtain in societyfar outweigh the differences.

This phenomenon is true for many reasons. In oursociety, most of us are brought up and steeped inthe same Judaeo-Christian, individualistic heritage.In addition, we live under the same set of laws,which encode much of that morality in ways thatguide and shape our theories and practices. Finally,it is evident that we could not live and functiontogether if we did not implicitly share a very signif-icant set of moral guidelines. This point is typicallyunnoticed precisely because it is always there andit works. What is noted and remembered are the sit-uations in which the point does not work and aboutwhich we are greatly divided — issues like capitalpunishment or abortion. If you X-ray very differentlooking people, what you see is very similar; if youX-ray a Hassidic rabbi and a Wyoming ranchermorally, the same thing occurs.

What aspect of our social ethic is being extendedto animals? In our democratic society, the consen-sus social ethic effects a balance between individ-uality and sociality, or more specifically, betweenindividual rights and social utility. Although mostsocial decisions and policies are made according tothat which produces the greatest benefit for thegreatest number, this is constrained by respect forthe individual. Our ethic builds fences around theindividual to protect the sanctity of his humannature, or telos, from being submerged by the gen-eral or majority welfare. Thus, we cannot silence anunpopular speaker, or torture a terrorist to find outwhere he has planted a bomb, or beat a thief intorevealing where he had hidden his ill-gotten gains.These protective fences around the individuals arerights; they guard fundamental aspects of the indi-vidual even from the general good. Specifically,these rights protect what is plausibly thought to beessential to being a human — believing what youwish, speaking as you wish, holding on to your prop-erty and privacy, not wanting to be tortured, and thelike. These rights are fueled by the full force of law.

One major step toward extending the ethic to ani-mals, not difficult for the average person to take, isthe realization that there exists no good reason forwithholding the ethic from our treatment of animals.In other words, there is no morally relevant differ-



ence between humans and ani-mals that can rationally justify notassessing the treatment of animalsby the machinery of our consen-sus ethic for humans. Not only arethere no morally relevant differ-ences, there are significantmorally relevant similarities. Mostimportant, most people believethat animals are conscious beings;that what we do to them mattersto them; and that they are capa-ble of a wide range of morally rel-evant experiences — pain, fear, happiness, bore-dom, joy, sorrow and grief. In short, they experiencethe full range of feelings that figure so prominentlyin our moral concern for humans.

Not only does ordinary common sense accept asaxiomatic the existence of consciousness in animals,it also takes for granted that animals have natures(telos) — ”fish gotta swim, birds gotta fly,” as thesong goes. Again, it is not difficult to get ordinarypeople to admit that the central interests of animals’natures should be protected from intrusion; even ifwe use animals, animals should live lives that fit theirnatures. It is not an accident that a major confine-ment chicken producer like Frank Perdue did not,in his advertising, show the public how he reallyraises chickens. Rather, he ran ads showing openbarnyard conditions which affirmed that he raised‘happy’ chickens. Ordinary people — even thosewho are not animal advocates — are appalled byveal calves in confinement, wild animals in tinycages, or primates in austere and deprived environ-ments. Polls indicate that 80% of the general pub-lic believe animals have rights. Well over 90% ofthe 7,000-10,000 ranchers I have addressed alsobelieve this. Indeed, the president of the ColoradoCattlemen’s Association remarked some years agoat a closed seminar for agriculture leaders that, “If Ihad to raise animals the way these veal people do,I would get the hell out of the business.”

In summary, society has gone beyond the anti-cruelty ethic and has expressed concern that ani-mals used by humans not suffer at our hands, and

indeed, that they live happylives. The rights of animals, asdetermined by their natures,must constrain and check animaluse. Convenience, utility, effi-ciency, productivity and expenseare not sufficient grounds foroverriding animals’ rights. Thisidea is tentatively encoded insome legislation, and it is affect-ing animal husbandry withoutbeing legislated; the extensiveefforts over the past decade to

create zoos that respect animal natures give testi-mony to the spread of the new ethic. Furthermore,it appears that society is actually willing to give upcertain animal uses and conveniences for the sakeof the animals. The abandonment of the Canadianseal hunt, the massive social rejection of furs, andthe rejection of cosmetic testing on animals by manycompanies, all without legislation, attest to the grow-ing hold of the new ethic.

Considering what we have discussed, it is patentthat the dairy industry should undertake a proactive,critical self-examination before society as a wholeis galvanized by some sensational event or exposeto legislate in an ill-informed way. The Minneapolis-South St. Paul stockyard situation could well havehad that effect.

You must become proactive in the face of theemerging ethic, not reactive and defensive. You musttry to separate the legitimate from illegitimate criti-cisms directed at your activities, and correct the realdeficiencies in an anticipatory way. It is far cheaperand easier to deal with things yourself than to havechanges legislated by well-meaning but ignorantpeople who don’t know hay from straw or foals fromponies. If legislation is necessary to correct abuse, itis far better that it come from you than that it beforced upon you. Legislation coming out of acrescendo of public pressure is invariably flawed.

If society can generate sufficient concern to passlegislation that mandates the control of pain of ratsand mice – the overwhelming majority of animal usedin research – imagine what a groundswell of concern


Polls indicate that80% of the generalpublic believe ani -mals have rights.Well over 90% ofthe 7,000-10,000ranchers I haveaddressed also

believe this.

could be evoked about dairy cows, the animal whichhas been called “mother of the human race.”

Let us examine the status and problems of the dairyindustry proper in the face of this new ethic, leavingaside the veal production issue for another discussion.

There is, historically, probably no area of tradi-tional, extensive, pre-industrial agriculture wherethe contractual, “we take care of the animals, theanimals take care of us” ethic was more fully real-ized than in dairy farming. What made dairy anespecially good example of the contract betweenanimal and man was the early realization that gen-tle, compassionate treatment of cattle leads to sig-nificantly better milk yield. Science has recently con-firmed what common sense knew for sure — thatthe variable that correlates most highly with milkproduction is the personality of the herdsman, andthat women generally make the best stockmen.

Thus, while few people considered range beefcattle to be, as it were, members of the family, suchwas not the case with dairy cows. A colleague ofmine who grew up on an extensive dairy farm re-calls that there was no bigger honor in his familythan to be named after one of the favored cows. Stu-dents still tell me of their father’s crying after thedeath of a favorite cow. Since dairy cattle were raisedfor their products, not their meat, the element ofkilling was not central to such farming, and animalsoften lived for a long time, even beyond what couldbe justified by productivity alone.

This view of dairying entered popular culture and,in my view, still makes the general public favorablydisposed towards milk production. The image ofBossy happily chewing her cud is a cliche, often de-picted in cartoons, and the Carnation Company hasindelibly stamped an entire generation or two withthe pastoral picture of “contented cows.” Few mem-bers of the general public would agree with theactivist statement I heard at an animal welfare con-ference — ”I can think of nothing more disgustingthan drinking the milk of another species.” Thus, thedairy industry would be wise to confirm this per-ception of concern, not erode it.

Yet there exist both genuine welfare issues andissues growing out of uneducated public perception

which could harm the enviable position of dairy inthe public mind. In either case, however, these prob-lems must be laid to rest. As the animal industry oftenremarks, in animal welfare perception is reality.Unfortunately, as Albright has forcefully pointed out,“very little organized U.S. research on dairy animalwelfare is under way. A library CRIS-USDA com-puter search from 1978-1986 with such key wordsas dairy, cattle, cow, calves, calf, veal, welfare,humane, or well-being revealed four projects activeand pertinent to this discussion.”

1. LARGE DAIRIESOne of the most dramatic changes in dairies,

directly relevant to public perception of the indus-try, is the rise of large intensive dairy operations, withup to 3,000 cattle maintained in relatively smallacreages. The small dairy farmer, with names for hiscows, is a vanishing breed, as land costs, labor costs,and capital investment costs increase. The publictends, with some justification, to equate large oper-ations with lack of concern and attention to indi-vidual animals. On the other hand, proponents oflarge, well-capitalized, intensive operations arguethat their operations, possessed of adequate money,and unlike small operations, not running on a shoe-string, are thus able to afford sufficient labor to lookafter the cows, and actually provide for more inspec-tion of animals, since mechanization and automa-tion have removed much of the ‘scut’ work. Araveand Albright have argued that this is true for masti-tis control. Supporting this view is the fact that,unlike sows, cows are relatively expensive andhighly productive (the modern cow can produce 10to 36,000 lbs. of milk per year), and thus carefulattention to the animal also benefits the producer.

Albright has argued that mechanization is no sub-stitute for stockmanship, a point echoed by others.Research into this question would be highly desir-able. If it is true that large operations increase indi-vidual attention to animals, such research couldblunt negative public perceptions of large opera-tions. If it is false, it would probably lead to revisionsin industry practice and to better management. Suchresearch might compare small and large dairies in



terms of a variety of parameters related to welfare.My key point is that the public must be convincedthat, regardless of size of operation, concern for indi-vidual animals is still operative.

One area which feeds the idea of callousness atlarge dairies, according to Temple Grandin, is thetreatment of surplus calves. She informs me that suchcalves often receive no colostrum and are shippedas young as one day old, before they can evenambulate properly.

Behavioral KnowledgeOne of the most needed research areas in dairy cat-

tle is fundamental, basic research into the normalbehavior patterns of modern dairy cattle under theopen conditions for which they were historicallyselected, something like what was achieved at Edin-burgh by Stolba for domestic swine. This will help injudging the extent to which modern systems meet theanimals’ natures. Unfortunately, there is no wild pop-ulation of Bos taurus analogous to the population ofEuropean wild swine which Stolba used as a basis forethological comparisons. The closest analogue maybe beef cattle maintained under range conditions, ordairy cattle still kept under traditional conditions.

At any rate, methodology must be devised, andresearch conducted, which will provide researcherswith a baseline ‘ethogram’ of natural behavior fordairy cattle, which can then be used as a rationalbasis for assessing current systems. Such basicresearch would be invaluable for welfare concerns.In addition, as Temple Grandin and others haveshown, knowledge of fundamental behavior is use-ful for handling and management.

As we have said earlier, behavior seems to beemerging as a focal point for welfare deliberations.At the same time, cattle show fewer stereotypies thanother animals, but do show some. It has been sug-gested that cud-chewing provides a built-in form ofself-stimulation which allows the animal to copewith austere environments, even as gum-chewinghas carried generations of students through boringlectures. Given our earlier explanation of the newsocial ethic, such basic knowledge of cows’ behav-ioral needs and natures is vital.

2. CALF WELFARESome of the major potential hotspots for the dairy

industry come from the treatment of calves. Mostfemale calves are used as replacements for dairycows. Various practices associated with raising suchcalves have been criticized on welfare grounds. Onesuch issue is the very early separation of calf frommother. Public perception suggests that such a sep-aration is stressful to both animals, since cattle underextensive conditions can suckle for some sevenmonths.

According to Albright, such separation is neces-sary in order to expedite human-cow interaction —cattle reared by dams or by nurse cows with nohuman involvement “are more difficult to calmdown, have greater flight distances,... circle contin-uously in the holding pen, and are difficult to trainto the milking routine.” In other words, the earlystress of separation may increase the animals’ wel-fare later when it becomes a dairy cow, since hu-mans have become surrogate mothers to the calves,as Albright puts it. On the other hand, the averageperson sees ‘removing a baby from its mother’ asparadigmatically abusive, even cruel.

It is obvious that the practice of separating calvesat an early age from mothers should be further re-searched, with regard to stress on both cow and calf,and ways of mitigating that stress should be exam-ined. Given that virtually all dairy farmers effect suchseparation, the issue is of considerable significance.

A related question concerns the optimal time forremoving calf from cow. This is currently disputed,most notably with regard to the provision of colos-trum. Some dairy farmers leave the calf with themother for up to three days to allow the calf tosuckle, to permit a mother-offspring relationship toform, and to render the cow’s milk free of colostrumand thus able to be sold. In contrast, others separatethe calf immediately and deliver the colostrumthrough a nipple-pail or bottle. Although it may seemmore welfare-friendly to allow the cow and calf thelonger period to bond, one can argue that separa-tion of the calf after three days, rather than at birth,causes greater trauma. According to Albright:


“When the calf is left with the cow three daysor more, it is more difficult to separate the pair.Excessive bawling, fussing, and breaking downfences occur when maternal urges are thendenied, and the cow will fret excessively whenseparated from the calf, resulting in decreasedmilk production.”Again, this points towards the need for further

research in minimizing the stress of separation. It isalso clear that close attention to separation of calf fromdam by the public could generate generate very badpublicity for the industry, given the sanctity of themother- offspring relationship for common sense.Research into raising calves on nurse cows, as is some-times done in the beef industry, should perhaps beundertaken. Dairy bulls raised on nurse cows growup less dangerous because still fearful of humans.

Another welfare issue concerns the housing ofcalves. In the U.S., it is most common to raise calvesfor about three months in individual pens or hutchesto which the calf may be tethered. Although suchhutches are an improvement over crates, as animalsin fenced-in hutches can move freely, they are stilloffensive to many people who dislike the restrictedspace and isolation from other animals. Despite thefact that probably the major purpose of individualhousing is disease prevention and ease of observingindividuals, many dairymen will allow calves tointeract with calves in adjacent pens or hutches. Royhas argued that calves are happier when they cansee one another, and most dairymen with whom Ihave discussed this issue tend to agree. Outsidehutches reduce calf mortality over inside ones.

Supporters of individual housing argue that dairycalves do better and develop normally if they arekept individually until weaning, especially in out-door pens. They cite higher survival rates, reduceddisease and reduced tendency for persistent inter-sucking among calves raised this way. Albright hasargued that the vice of intersucking which is preva-lent in Europe is a function of early group housing.

A different view is expressed by Kilgour and Dal-ton, who favorably cite work by Sambraus to justifythe importance of keeping calves in groups to ensure

appropriate resting behavior, social and activitybehavior:

“The calf’s surroundings should provide plentyof stimuli to allow exploration and play.”Similarly, Fraser asserts that:“Individually reared calves cannot interactmuch with one another and long periods ofsocial isolation lead to failure to develop nor-mal social behavior.”Strangely enough, some research has shown that

calves individually raised in isolation, though indeedsubject to a chronic stressor, nevertheless producemore milk as adults. This is open to many interpre-tations, ranging from the simple notion that this is aclear case where individual productivity is not amark of welfare, to the complex notion suggestedby Albright that:

“Isolation stress has an organizational effect onthe ontogeny of the hypothalamo-hypophysial-adrenal system of neonatal calves. The resul-tant stronger response to adult stressors couldincrease milk production.”In general, given the diversity of opinion cited

above, as well as the strong tendency of the non-agricultural public to react negatively to isolation ofcalves, research and public education should con-tinue in this area. Ideally, such research could gen-erate group systems which do everything that isola-tion does, but allows the calves to enjoy social inter-action. According to Fraser:

“With further refinement of management pro-cedures, [straw-based] systems are likely to [be-come]... the normal method of calf housing.”

3. HOUSING SYSTEMSThe dairy industry in the U.S. employs a wide

variety of housing systems for dairy cattle, rangingfrom highly extensive, very traditional pasture sys-tems, to stanchion or tie-stall housing, to freestallhousing. There are positive and negative features rel-evant to welfare associated with all systems, butsome seem to be more problematic than others.

The system of greatest concern is probably tie-stalls, where the animals are tied in one place for



long periods of time. Tie-stallsare used almost exclusively inthe Midwest and Northeast.Although the apparent histori-cal motivation for tie-stalls hasbeen concern for the well-being of the cattle as well asreduction of labor, with tie-stalls allowing for ease ofobservation and inspection ofthe cows, the fact that the ani-mals are unable to move andunable to engage in normalbehavior, notably grooming, makes tie-stalls a veryplausible and inevitable target for social concern.Whereas a range cow will walk over 6,000 metersa day, a cow in a tie-stall is clearly prevented fromsuch exercise. In addition, the cow’s social natureis frustrated by such housing systems. Getting upand lying down can also be a problem in poorlydesigned stalls. Many tie-stall operators will let thecows out onto pasture or dry lots for one to fivehours a day when weather permits, but will keepthem inside during bad weather.

Many dairy cattle, especially in the West, are keptin drylot conditions, in outdoor dirt pens in groups.The cow’s social nature is expressed, and she canexercise. The problems with dry lots are similar toproblems of feedlots: lack of shade, lack of shelterfrom wind and snow, poor drainage, and generallack of protection from climatic extremes. Somefarmers do provide shade and cooling by use ofsprinklers. In general, cattle withstand cold stressbetter than heat stress.

Freestalls have gained in popularity since theirinvention in 1960. In such systems, cows can be intheir own bedded stalls and move freely into con-crete or earth yards where they receive food andwater. Poor flooring in these systems can lead to footand leg problems. Given a choice, dairy cows pre-fer other flooring over concrete. Research is neededinto flooring which reduces slippage and injury, andinto more effective sanitizing systems for waste re-moval. Poor hygiene in stalls can also cause masti-

tis. Again, research is neededto improve the systems.

One problem with all of thesystems described above isthey fail to allow for grazing onpasture, an activity for whichcattle have evolved and which,if permitted, they will spend 8-10 hours a day doing! (Indeed,one can argue that the domes-tication of cattle resulted pre-cisely from their ability to con-vert forage to food consumable

by humans.) Recent Swedish legislation aimed atrespecting the rights of animals following from theirbiological natures stressed the need for cattle tograze, and indeed granted cattle the right to graze,in perpetuity. It is likely that public opinion in theU.S. similarly favors the grazing of cattle. Few pas-toral images are as powerful and pervasive as thatof cows on pasture.

In any case, systems of housing which respect theanimals’ natures should be sought. I do not think thatthe new ethic will accept total confinement of cattle.

4. OTHER WELFARE PROBLEMSCastration, Dehorning and Branding – As in beef

cattle, dehorning is a problem, as is castration with-out anesthesia of bull calves. Most operators do notbrand dairy cattle.

Tail-Docking – Over the last few years, dockingof tails in dairy cows has gained in popularity in theU.S. and Canada. It is alleged that tail-docking re-duces mastitis and somatic cell counts. This is oftenaccomplished by elastrators. Allegedly, the proce-dure is painless and keeps the cow from flingingmanure. Conversations with dairy specialists, dairyveterinarians, and a lactation physiologist have con-vinced me that there is absolutely no scientific basisfor claims about the benefits of tail-docking. Prob-lems with mastitis are largely a function of hygiene,arising when animals are regularly down in uncleanstalls. Removing the tail is another example ofattempting to deal with what is a problem of human


Recent Swedishlegislation aimed at

respecting the rights ofanimals following fromtheir biological naturesstressed the need forcattle to graze, and

indeed granted cattle theright to graze, in perpetu -

ity.

management by mutilating the animal — e.g. ‘devo-calization’ of dogs, declawing of cats, and dockingtails in piglets. In this situation, however, unlike theothers, the procedure will not even deal with theproblem. Indeed, removing the tail will cause addi-tional suffering to the cow, since it can no longerdeal with flies!

Not only is docking the tail in fact not curative,it can exacerbate the problem. The use of elastra-tors, contrary to the belief of some farmers, is quitepainful. Use of the elastrator can also cause infec-tion, death and decreased milk production. In purelyprudential risk-benefit terms, then, it is irrational tochoose to dock the tails, and since there is no poten-tial benefit from the procedure, the farmer is notrationally warranted in taking any risk whatsoever.The same point, of course, holds regarding surgicaldocking of the tail.

Indeed, there is reason to believe that docking thetail is likely to increase the very problem that thefarmer is trying to eliminate, namely high somaticcell counts. Kilgour and others have reported thatstress elevates SCCs in dairy cattle, and the use ofthe elastrator and the subsequent pain and distressthat it causes the animal would certainly representa stressor, as would any resultant infection. Further-more, since stress results in immunosuppression, ananimal experiencing the docking procedure wouldsurely be more prone than ever to mastitis, since itsimmune system is being compromised.

It appears to me that the non-invasive alternativeof clipping the tail switch should work as well asdocking if there is anything to the theory implicat-ing tails in mastitis. The issue should be definitelydealt with as a welfare concern.

Mastitis and Lameness – According to Fraser andBroom, lameness and mastitis are the two majorwelfare problems in dairy cattle, and that there is apositive correlation between the incidence of bothdiseases. Lameness has in turn been tied to high pro-tein and high concentrate diets. Lameness can bereduced by hoof trimming and foot baths, and byattention to flooring, but much remains to be dis-covered about the conditions which lead to indi-

viduals being likely to become lame. A good dealof lameness is a result of laminitis. Thus, we have amajor tissue of researchable issues here, preferablyundertaken in tandem with research into improvingstall housing and controlling mastitis. Many of theseproblems can currently be handled with good hus-bandry and labor which is ‘cow smart’. The chal-lenge, as in all of modern agriculture, is to make thesystems ‘idiot-proof’ in the context of larger andlarger operations. Research into better flooring,waste disposal, sanitation, and diet would help cre-ate systems which are welfare-friendly, even whenstockmanship is not perfect.

Downer Animals – The dairy industry is probablythe major source of downer animals, and has tendedto block legislation against this horrendous practice.While increasing numbers of dairymen are beginningto realize that nothing is more erosive to the contentedcow image of the dairy industry than transporting andthen dragging a downer cow with a tractor or loaderto the kill floor, other elements of the industry haveturned a blind eye to the problem. Most dairy down-ers are probably a result of calcium-phosphorusimbalance leading to milk-fever (hypocalcemia).

Animals that are down should be killed on thefarm and not transported. As one rancher put it, “weshould eat our mistakes.” The industry should proac-tively develop or support legislation outlawing it.Both state and federal initiatives are pending regard-ing downer animals. Not acting decisively on thedowner issue is probably the greatest current threatto the dairy industry in terms of public perception,and is also the most morally reprehensible practice.

Future Technology – Future technology is mov-ing quickly into the dairy industry. All technologi-cal innovation can have major implications for thewell-being of the cows. Consequently, all new inno-vation must be researched in terms of welfare impli-cations at the same time they are being researchedfor productivity and efficiency.

The rise of automated computerized milkingshould be carefully monitored. It has been arguedthat “this could allow the elimination of the milkingparlor, because cows could at their leisure enter



stalls to be milked automati-cally. More frequent milkingwould increase productionand place less stress on theudder. An important benefitwould be to allow the stock-man to spend more timeobserving and tending his ani-mals and less time on routinelaborious work.” On the otherhand, such an innovationcould go wrong in manyways, lead to less attention tothe animals, and further erodethe bond between humans and farm animals.

Genetic engineering can also cause problems.Recent unpublished work on double-muscling ledto unexplained weakness and paralysis in calves.Other animals (pigs and chickens) engineered forincreased size have shown a variety of problems,notably foot and leg problems, since foot and legstrength did not increase in proportion to the addi-tional size. Cloned calves have been extremely largeat birth, leading to birthing difficulties, and haveshown other problems, including alleged ‘stupidity’.In all genetic engineering programs, the resultant ani-mals should be no worse off than their parent stock,and should be carefully monitored. Productivityshould not be pushed at the expense of welfare.

The use of BST and other similar growth hormoneinnovations developed through biotechnologyshould also be monitored for effect on cattle well-being. It has been argued that the use of BST willamplify a problem already prevalent in the dairyindustry as a result of artificial insemination. In eval-uating A.I. Sires, a major criterion employed is thefirst lactation production of the bull’s daughters.Unfortunately, a bull may be bred to thousands ofcows before an evaluation can be made of the lon-gevity of his daughters. The result is strong selectionpressure for high first lactation production and weakselection pressure for longevity, a major factor in

efficient production. We arethus selecting for a 100- meterdash cow, forgetting that themost profitable cow is themarathon cow. Thus, manycows are culled before theyreach their (theoretically high-est) fifth lactation, during thethird lactation. BST could aug-ment this problem. Canadianresearch showed that “BSTtreatment was associated withan increased culling rate pre-sumably as a result of increased

stress associated with higher milk production.” Thestudy showed that while BST increased milk pro-duction by 14.4%, it increased culling rate by 45%

According to this argument, this dramatic rise inthe culling rate as a result of the injection of BST isfurther confirmation that we have, through naturalselection, bred cows to produce a level of BSTwhich jeopardizes their chances of surviving untiltheir most productive years. Injecting additional BSTmakes matters worse. The use of BST definitelyincreases the incidence of mastitis in dairy cattleperhaps because the animals are giving more milkand the lactation ducts are more patent and thusmore susceptible to bacterial invasion. Social accep-tance of BST has of course been highly equivocal.Widespread public knowledge of the deleteriousconsequences of its use to the animals could seri-ously harm the industry’s stature.

ConclusionThe dairy industry, by and large, has not been the

target of negative publicity, except as the source ofdowner cattle, as we discussed earlier. The prob-lems we have discussed should be aggressively dealtwith in order to preserve the industry’s enviable posi-tion in the public mind and, more importantly, topreserve the fundamental decency hitherto built intoour ancient contract with these animals.


Not acting decisivelyon the downer issueis probably the great -est current threat tothe dairy industry interms of public per -ception, and is also

the most morally rep -rehensible practice.



notes

Do You NeedMore Copies Of

This Book?

Additional copies of theproceedings of the 2nd Western

Large Herd Dairy Management Conferenceare available for $20 each by contacting:

Cooperative Extension Service,New Mexico State University

Box 3AE, Las Cruces, NM 88003-0003(telephone 505-646-6404)

2ND WESTERN LARGE HERD DAIRY MANAGEMENT CONFERENCE • LAS VEGAS, NV • APRIL 6-8, 1995

Agrimerica, Inc.Agripro Biosciences, Inc.

Alfa Laval Agri, Inc.Alltech, Inc.

American Breeders ServiceThe American Jersey Cattle ClubAssociated Milk Producers Inc.

Aurora Dairy Corp.A.L. Gilbert Co.Babson Bros. Co.Bank of America

Bank of the SouthwestBraden Start Bottle

California DHIACargil, MLPD

CBP Resources, Inc.Church & Dwight Co., Inc.

CMW NutritionColorado DHIA

Custom Dairy PerformanceBou-Matic, Div. of Dairy Equip. Co.

Dairy Health Equipment Service & SupplyDairy Nutrition Services

Dairy Profit WeeklyDairy Today MagazineDarling International

DaSilveira Southwest, Inc.DHI-Provo Computing Service

Diamond Cross, Inc.Diamond V Mills, Inc.

DRPC@RaleighElanco Animal HealthFranklin Laboratories

Germania Dairy AutomationGreat West Analytical

Holstein Association USA, Inc.Ivy Laboratories, Inc.

J.R. Simplot Co.Kamar Marketing Group, Inc.

Klenzade

Korral Kool, Inc.Land O’Lakes

Landmark Genetics, Inc.Loveland Industries, Inc.MacGowan-Smith, Ltd.

Masstock Saudi Dairy FarmsMerricks, Inc.

Mid-America Dairymen, Inc.Milk-Rite USA, Inc.

Min-Ad, Inc.Monsanto CompanyNew Mexico DHIANorel Corporation

Nutrius/Bioproducts, Inc.Ozone Water SystemsPaul Mueller Company

PBI Parlor SystemsPioneer Hi-Bred Int’l., Inc.PCA of So. New Mexico

Protocol-Performance Products, Inc.Purina Mills, Inc.-Missouri

Purina Mills, Inc.-TexasRanch-Way Feeds

Rhone-Poulenc Animal NutritionThe Schleuter Company

Select Sires, Inc.Semex USA WestSire Power, Inc.

SmithKline BeechamSSI Corporation

Texas DHIA3M Animal Care Products

United Dairymen of ArizonaThe Upjohn Company

U.S. GenesWest Agro, Inc.

The Western Dairyman MagazineW.S.I. Western Stockmen’s

Zaugg Dairy NutritionZinpro Corporation

The Organizing Committee of the 2nd Western Large HerdDairy Management Conference wish to thank the following

companies and organizations, without whose generous financialsupport this event would not have been possible:

95wdmc proceedings of the western large herd dairy ...wdmc.org/1995/95wdmc.pdf · with dairy...

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